I have had Tube Tech eqs, mic pres and compressors since the 80s. If you are looking at used compressors . . . don't forget the CL1A compressor which you can most likely buy cheaper . . . . same thing as the 1B.
...the 500 series slots for tracking vocals and such. We have racks of vintage Pultecs, 1176s, and dbx160s, VariMu, and CL1A along with a few Amek EQs. Maybe even adding an 8 channel rack of useful EQs would help us out for larger tracking. I can see the 8424 not working out for many...
...pros and cons of every variety....I ended up with the Manley Elop, which is their cleaner version of an LA2A....Tubetch CL1A or CL1B also does a nice rendition of this sound.....
Anyways -- best of luck on your quest....!