via this auction and this auction
On the Precise Model 635:
"A.F. Sine, Square, and Pulse. SN# 2656. Vintage unit powers up but is otherwise untested; sold as-is but everything appears functional and this unit has been thoroughly cleaned."
Not synthss, but rather a cool piece of test equipment. You can see the seller's other items for more. Would make for interesting DIY cases. Thomas Dolby has been known to use similar devices [see this post].
