It would likely be faster to ask a semiconductor company if they had a transistor in house that could be used in place and give them the 7530's older specifications and that it was going to be used off-label for RF production and see what they say. Hit the major players up and sit back and see what they say. I have tracked down harder things to find like trying to find the machine shop in Taiwan that made a particular part. I have down it from photographs and calling around on more than one occasion to find a supplier that could match the quality and production demands I needed at a price point that allowed me to remain competitive. It is never easy but in this case, all you need to do is email or call semiconductor companies with a specification and see what they say. For the record, I have done that in the automotive trade, musical instrument construction and aviation parts. So I know a thing or two about doing it. I just do not have a dog in the fight when it comes to electronics since I only work on my own gear.
I know this much Palomar is not having anyone spin up a custom part for them you know it is off the shelf. So at the very least, we have that working in our favor. That said it is still like looking for a needle in a haystack. The only other thing we know for sure is that it is some Chinese made part by a company without a solid reputation otherwise they would use that companies name.
I just had to send back some clutch parts from one two different USA vendors. One sold me an Exedy Clutch kit but it did not contain Exedy Parts they were easy to spot Chinese fakes with no country of origin, no part numbers, no name brands on any of the parts. The company claimed that all of their parts were made in Japan or America. If a part is made in Germany, Japan, USA you always want that on the part because you command a premium for the parts and they sell themselves. The other company did similar they showed a Seco made clutch disc Made in Korea with part numbers etc laser engraved on the part and rebranded Valeo on the part as well. What I got though was a completely different part than listed. Different design, color, friction material, sanitized part again with no country of origin, no part numbers no brand name etc.....The only reason to have a sanitized part is if you would not want to be associated with the OEM because of the country of origin, quality control or price point.
Sadly people always want to maximize their profits and often that means secrets and lies! I never feel comfortable staking my reputation on any part that is a generic jelly bean parts. I always want to know who is making the parts I am using. Like I said in the above people will often pay a premium for parts amde in Japan, Germany or the USA or made by a company you trust to have quality control even if it is made in China so a Sony, Fujitsu, Toshiba, Motorola made part that is made in China, Israel, Korea, Mexico etc...Why? Because we know that even if it is being made in China or India that those companies are still demanding good quality control standards.
