New coppers and o-rings will fix it right up. The cooler works very well, and coupled iwth 8 quarts of oil in an F engine, you get excellent oil life and engine protection from it.
The other bolts are just plugs and such for passageways when they were machined and as desertpat said, one is a relief valve for the oiling system on the 2F, worth cleaning all passageways, also pull the sender and clean that as well, while it is all apart.
Only flaw I had on mine was the heater hose that leaves the front of the cooler and goes to the lower radiator hose. The orginal hose was expanded about twice its size and very soft. Appeared to be degradation from oil dripping on it from oil changes and such. Just watch that hose, and you should be fine. Of course it took about 20 years for the hose to come close to failure due to oil exposure, so you should be fine
I recall picking through NAPA assortments until I found the right copper washers and o-rings to fit mine years ago. I think the plug bolts will also have copper washers to seal them. Sometimes a copper washer can be reused. At least on the plug bolts, if they don't leak, you are fine, but I would replace the big ones, as they are tougher to deal with after the engine gets dirty behind the cooler.