FYI--There were three versions of the 8417 amps. The first and second versions used the Philips/Sylvania 8417 with 12Dxx inputs (can't remember exactly which tube), the second used 12AX7, 12AU7, or 12BH7 (which it sounded amazing with...but I digress) driver tubes. The final version used GE 8417 with the same driver tubes as the second. As you know, don't use the GE's in the amps designed for the Philips/Sylvania without modding them first.
I wish you success in finding a set, with the right tubes and speakers, those amps can sing! The 8417's are getting scarce, but there has to be a few sets out there somewhere. I'll let you know if I run across any.
Lee