I've seen 10+ year old seeds pop just fine with my own eyes with high (>50%) germination rates.
If they really were stored cool and dry, I wouldn't at all be surprised if you could get some 40 year old seeds to germinate, especially if you have a full 30 of them to start with. Again, only one way to find out for sure.
Scuffing the shells with an emery board to increase water penetration is perfectly fine; just don't go crazy there.
Personally, I would definitely NOT add "hot" water to the seeds! IMO, that's a great way to ensure that none of them germinate.
Also, if it were me, I'd try germinating in small batches of 5 or 6, both to keep the numbers manageable, but also just in case the germination rate is better than you expect.