Will a standard corny rebuild kit work on the oval shaped lid?
Those are both “standard” lids which are oval and the lids are interchangeable on both the pinlock and ball lock kegs. There is another style of lid called a racetrack lid, but that’s not what you have. For your lids, one has a static pressure relief valve originally found on most of the pin lock kegs (Coke kegs) and the other has a manual relief valve. If you pressurize the kegs and the valves don’t leak, I wouldn’t worry too much about doing anything with them. If they do leak, you have a couple options. Either replace the valves, or replace the entire lid assembly. The
static valves are becoming increasingly hard to find, and the particular manual valve on your other lid is an obsolete style that might be hard to replace. You can find new lids
like this by doing a google search. The dents are mostly cosmetic and nothing to be concerned with. One other thing to be aware of is the o-rings on the pinlock posts are a slightly different size than the ball lock posts.
I did get the 20# co2 tank also and it is aluminum. Score I hope?.
That should be a good tank for a swap/trade. As mentioned above, it is WAY out of certification. Unless there’s another stamp somewhere, it was last certified in September 1981.
The certifications are good for 5 years. That doesn’t mean there’s anything wrong with that tank, it just needs tested again before it can be filled. Depending on the company you deal with for refills or swaps, be prepared to pay a recertification fee. Are there any other stamps that look like the one I circled above?
Regardless of the issues everyone has mentioned, you got a hell of a deal even if you have to do a little maintenance.