I would give this a try. Phil used the preamp out of this amp for a while in the 80s. It's a pretty good sounding amp (I'm not fan of SWR speakers, otoh).I have an SWR workingman 400 watt solid state amp as well. Do you think I'd be better off trying that? I really like the sound of the tube amp though, especially on the highs. I also have a Jazz but I tried that and always go back to the P. I noticed that Phil played a Jazz for a bit there though. Any ideas what strings he was using while playing that one?
While Phil was using a Jazz, my guess for strings the first time around would be whatever flats were available (ca. mid 60s), second time around, maybe D'Addario half-rounds.
If you really want to go nuts, and be like Phil in terms of increasing the level of high-tech, split the output of your bass so each pickup gets its own amp. Run the lows through the SWR and the highs through the tubes!