I did my first bike restoration/refurb on an '85 Schwinn World Sport, which was also free. That was five years ago and the start of this madness. Enjoy the process!
For me, I'm reassembling my big hoss Nishiki rain/end-of-the-world/winter commuter bike after 9 months, 5-6 of which were during Seattle's record-breaking winter in regards to rain. Brutal stuff. Full tear down and cleaning of every part left me with grey-black hands many times (to the Dawn dish soap we go! Again!). For being a 68cm frame, having 700x35 tires (Michelin Pilot Trackers, which are heavy yet bomb-proof) and full fenders keeps her proportional. And I now have a metallic red bike again!
Bit of a parts change out. I ran super smooth Sora 3x9s to a 105 5503 triple FD and an XTR Rapid Rise (haha!) with a 52/42/28 Biopace-ringed Ultegra crank and an 11-34 cassette--flawless setup, meaning you can do it too with nobody to tell you it won't work/work well! Now, having resurrected 7700 Dura Ace 2x9s that I got for $10, I'm putting a 6600 crank (53/39) and changing out the XTR RD for my bought-new Sora 9-speed. 32T cog limit but it, via hand actuation, clears the 34T cog. If it doesn't work, I'll just go back to the XTR.
Shorter stem installed, new rear pads, and I'll eek a little more out of the big orange/rain pads in front. Larger front fender flap now goes to 1/4" off the ground (such a cool look, and should keep me drier), and a few adjustments to the fender's setup and positioning should allow me to run the front tire at 60 PSI vs 40-45 PSI as before the higher pressure caused rubbing... You can run these babies at 30 PSI no problem (at least in the front) as the sidewalls are about 1/8" thick--you'll be slower, but you won't notice deformation. Hilarious.