Chastened by the most of my replies, I went out to buy a used lid for my 7.5 inch frypan. A tour of 2 Goodwills and 2 Salvation Armys found me one at the 3rd stop. It fit pretty well, wobbled a bit, but otoh, my pan doesn't have vertical sides. The side are rounded and taper inwards, so figuring this may be the best I can find, I bought it with its original little teflon-covered pot, for $5. At the 4th store, another Goodwill, I found the exact same lid, except with a different handle, on an all metal Farberware pot.
I will be near two more Goodwill stores over the weekend and I'll keep looking. (There are two other Goodwills I pass by every month or so. Knowing me, I'll look there too.)
Questions: I tested the lid tonight. The first egg's yolk broke. :( Normally I would scramble them after that, but I bravely pressed on. The second egg didn't break. The lid worked well. The white on top didn't sit around uncooked long after the bottom was cooked; and the top of the egg seemed as hot as the bottom when it was time to eat. Hurray.
But I could barely see anything because the inside of the lid steamed up.
1) How to prevent steam-fogged lid?
2) Assuming a lid with a pot or pan it was meant for, how come some lids have a vent hole in them and others don't.
BTW, it was indeed much better to buy at a thrift store than on the web, because I could tell how well it fit. And less than half the price, and with a free little pot.