Hi Toad,
If you don't have an inline RF wattmeter and a dummy load, then you are really flying blind here. A DVM is okay to troubleshoot a lot of common breakdowns, but if you can't verify what's coming out of the radio on transmit, that's a problem. That would be VERY helpful to know.
As to your use of the "Diode Test" on the DVM.. Did you check each diode twice? Once with the banded end to the black probe, and again with the banded end to the red probe?
A normal reading with the banded end to the black probe would be between 0.600 and 0.700. The reading with the diode pointed the other way, with the band to the red probe, should be an open circuit, as if the probes weren't touching anything. The diode must turn ON pointed one way, but must ALSO be OFF, when pointed the other way. Unless you checked EACH one BOTH ways, you can't say that any of them are good, yet. This is the basic character of a diode, that it conducts in one direction, but NOT in the other. You gotta see both sides of this characteristic, to know that it's good.
One clue in your last post, about the RF meter slamming on transmit (I think that's what you meant), suggests to me that the connection from the antenna socket has been clobbered. It would be very helpful to know if any transmit power is coming out of the radio. If not, it's time to find out where the connection from the antenna jack has been blown apart.
L4 has a very tiny inductance, not much more than one microhenry on one winding, less on the other one. Hard to measure with a proper L/C meter, but hopeless on a DVM. Just because it shows continuity does not mean that the windings are okay. A lightning pluse can fry the enamel insulation on the tiny wire windings inside. The DVM will still show continuity, but fried windings don't deliver RF from the antenna to TR14. If your DVM had said that the windings on L4 were an open circuit, that would be a clear failure. Just because the continuity checks okay, you can't be sure L4 will tune properly.
C31 has only 12 pf of capacitance. A DVM can't measure that, unless it has a "C", or capacitance scale. Only the really high-dollar meters include that scale. A correct DVM reading on C31 is an open circuit, as if you had not touched the probes to it at all.
The one 1000 uf cap I know is C172. The reading in the 2000 may be from the failed AC power supply, or more likely from all the lights on the front panel. The 148 probably has a blown light bulb in the S-meter, making this reading higher. Several of the front-panel lamps in the 2000 are wired in parallel with that cap. Checking it while soldered in the circuit will not tell you a lot about that cap. The DVM will be reading the resistance of those bulbs, in parallel with the cap.
One other detail. You can't use the radio's chassis to ground your DVM's negative lead. The chassis is 'floating', connected to the circuit-board's ground circuit through a dozen or so disc capacitors. They make the chassis into a ground for RF currents, but NOT for a DC ohmmeter. The reason for this goes back 30 years, to a time when some cars had the POSITIVE side of the battery grounded to the vehicle frame. Mostly this would be MACK brand tractors 30 or 40 years ago. This "floating ground" arrangement allowed you to use the radio in either type vehicle, positive-ground OR negative-ground. Since the DC power socket's negative side is NOT hooked directly to the chassis, the radio will work in a 1972 White or 1974 Mack OTR tractor. Pretty sure the truck industry went totally negative ground years ago, but the CB manufacturers still use the floating-ground hookup, even now. To make a measurement like the one you describe, the DVM's negative clip should go to the negative pin on the DC power socket, or to the negative lug on the big filter cap underneath, the one held down by the metal clamp.
I can't escape the suspicion that this radio has gone beyond the "DVM only" limit. Lightning damage can be a real pain. Once the radio comes back to life, hidden damage can cause the receiver or transmitter to still be "weak". Alive, but not nearly as strong as before. A DVM won't help much in that situation.
A reputable shop will not quote a price for this kind of job without a chance to see it and do the troubleshooting first. Especially with a lightning job. The best way (I think) is to charge a fixed "bench" or "estimate" fee. This way, the shop gets paid for the labor they invested in adding up a total price for the job. The customer knows how much he risks spending for "just" bad news, itemized in dollars and cents. Nobody wants to write a blank check and say "fix whatever's bad". Nobody with a clue, anyway.
One (of several) reasons we don't solicit work shipped in is what it does to the price of "bad news only". If I charge 25 bucks to diagnose a 2000GTL, and the estimate totals 200 bucks, the customer is (rightly) going to say "No thanks". All he owes is the estimate fee, and takes it home not repaired, no hard feelings.
Add to this the cost of packing, insuring and shipping the radio twice, and that 25 bucks jumps to 70 or more. Pretty high price for "just" bad news, if that's what we find. Yes, I have other (good) reasons for not soliciting work shipped in, but this is a good reason all by itself. Seventy bucks (or more) for just bad news? Gotta figure people would gripe.
And about that "worth" part. What it's worth is pretty much what your other choices would cost you. If you can replace the radio for 150 bucks, this one can't be 'worth' any more than that to you. Mostly I can sidestep the "worth" question. Most of my customers seem to know what another radio will cost them, before they bring one in to get fixed. Once I present them with an estimated job price, they have a way to compare the price of that option to the price of chucking the radio and starting over with another one.
My gut intuition is that even a pro isn't going to get this one going with just a DVM.
73