I tried to sell a Wilcox-Gay Recordio model 4F10 at the NEARC Westford show this past winter. I had rescued it from the town dump. It was clearly someone's prized possession, as it had all its accessories, an original service manual, and a telephone pickup coil in its original box. But old mono reel to reel tape recorders aren't very interesting to most collectors, so no one was buying.
One fellow wanted me to open it up and sell him the tubes from it. I finally gave in and pulled the tubes; he did score a single Ampex Bugle Boy 12AX7, but had hoped to get two. The second 12AX7 didn't have any notable markings.
I put a "free, take me" sign on the remains, and some young fellow did eventually do that. I regret selling off the tubes; I should have just given the whole works away. But then it probably would have been scavanged for tubes anyway and dumped.
Anyway, I did make a scan of the Wilcox-Gay Recordio 4B10 and 4F10 Service Manual. It's also linked from my Liberated Manual list in the nav-bar to the left of the page.
I also made a gray-scale scan of the manual. It's much bigger, but the photos are better. I should have tried a 600 dpi black and white scan with descreening; that probably would have been the best compromise between file size and quality.