most transistors do show "open line" between the C and E junction, and the test in that video is correct.
its just that the 1969 happens to be one of the weird ones.
i sometimes wonder how many good 1969's have been junked over the years due to this.
if you are getting 7 watts out of the radio, then the final is good.
the driver cannot produce this much power on its own.
low power problems can be a real bear to track down, so the very first thing you want to do is completely eliminate any outside possibilities like the power supply.
hook a voltmeter to the power jack on the back of the radio, note the voltage (should be between 13 and 14 volts give or take), then key the radio and look for any voltage drop.
then hook a current meter in line with the positive lead into the radio and again key the radio up.
you should notice the amp draw go from a few hundred milliamps to almost 2 amps depending on where your deadkey is set.
of these two tests go well, then you can look inside the radio.
if they dont, its time to switch power supplies or check in the radio for old leaky electrolytics that attach to PC board ground.
if the power supply checks out, first find R187, and connect a DC voltmeter to the end of it that is opposite VR9.
key the radio and check that you have 8 volts on this line.
if it is lower than that, you'll have to start checking components that are in parallel with this line.
if that goes ok, try pulling VR9 completely from the board and make sure that it makes a smooth resistance change across its range like it should.
if it acts funky, try replacing it. ive seen them go bad before.
other things to check are C191, R187 itself, D50 (the bias diode), and C156.
this is just a few that popped out at me.
all this is assuming that you can adjust bias on the final like normal.
if you cant, then there is more to it.
after all this, you might just have a crappy 2166 that is just very weak but still tests good.
the pre-driver (2SC1973 or 2314 usually) could also be crappy.
its not very common, but it does happen.
good luck,
LC