If you look really hard you can buy a brand new API 550b for not very much more than that, just makes sense to buy a new one. The api reissue of the 550A is waaaay more money than the B which has to be the most moronic thing Ive ever heard of. Honestly, who the F cares if the switch is handwired or if it is PCB mount? Honestly? I would be shocked if they sound different, they MUST be using the same opamps for both. It would have made sense to make the A cheaper than the B since it is three band, that would have beeen cool, who is gonna buy a more expensive three band EQ when you can get a 4 band with more points, more flexability that sounds exactly the same. Talk about vintage hype, what a wierd decision for api to make. I think I prefer the 550 over everything, whatever they were using for opamps back then, the 550's I have are way more mellow sounding than my 550a or b's. I was suprised to see BA offer a new EQ that is priced identically to what you'd pay for original API equipment. Wierd.
I have been wishing for a billion years that someone would offer somethig to fit the api form factor but SOUND DIFFERENT. Ron, if you do an EQ, stick a totally different sounding opamp in there. That would be really slick and could be a good $$$ maker if you did it right. Some kinda ultra saturated sounding opamp in there would kill.
dave