I'm also working on restoring an old (~1960) Eico HF-81 stereo amplifier, as part of my continuing journey into tube audio. I picked this up at ebay, for whatever that's worth. It's apparently been in a basement for years, and it was cobweb city under there, but I've cleaned it out, and I'm in the process of mapping the resistances in the circuit. Unlike some other audio equipment I've had the displeasure of repairing, this was (as a kit) meant to be worked on by humans. By all accounts, this can be a sweet-sounding amp, but I'm not powering it up until I have everything mapped, and I've replaced the power cord, which is iffy at best.
I've been using the Web extensively for research into general tube information, components, prices, advice, etc. A good source of general HF-81 Information can be found at that link, and I've gotten some pointers and some very good email suggestions from Roger Stevens, who has a page of modifying the HF-81 that you shouldn't start without checking.