I picked up my bass today because I thought I might be able to use it tomorrow (no, the new switch didn't come in). I detected almost no improvement since last time, maybe a bit less hum, but still really low volume, and switching modes just adds a lot of mids (and more hum). I took the pickup cover off, experimented with touching things, i found the hum increased dramatically if I gripped onto the sides of the coil (which is wrapped in some sort of plastic tape, mind you) that's closer to the bridge with my fingertips. Gripping onto the sides of the coil that's closer to the neck had no effect at all. I dug out the weird little unit that handles the switching between the two modes (it just sort of sits there in a little rout in the pickup cavity), moved it around, poked around on it and the solder joints with my fingers, etc. I had some definite effects on the amount of hum, from getting rid of most (but never all) of it, to creating extremely loud insane hissy hum. The sad thing is, through all this dysfunction, I am still able to tell that there is good sound in there somewhere; it's just not being allowed to shine through. But I am way past frustrated with it, I'm giving up. I think I'll just get rid of it and look into acquiring a reissue Harmony H22 (still waiting for news/info/pricing to be published)...
So yeah, I think I would definitely recommend against putting one of these pickups in a reissue Rivoli. For all I know, the pickup may work beautifully (it did test at 31k), but the bass itself is just too shabby. At least the one I have is. And anyway, the pickup pole pieces are a little too far apart for the Rivoli string spacing. WHich is something I could have overlooked if everything else was working right. I don't know, I think the issue might be with the damn baritone switch unit (not the switch button itself, but the little unit that it's wired to). I don't know, maybe someone else with techinical experience with and love for these particular basses would be able to gut out the bad stuff and put in better stuff and turn it into a wonderful instrument. But that person would not be me. I just want it to go away. I'm just so far past the point of caring and hoping for this bass that I don't even want to look at it.
/sorry for the pathetic venting but I'm really in a foul mood now. I could use a drink or three, but getting tipsy at home alone is just no fun. bleh...