Max torque on those linings is not all that dramatic.
If you have about 2:1 primary ratio, then you have about double the engine torque as a max, plus some shock loading on hard shifts. Probably under 100 ft-lbs at max. You can turn a torque wrench that hard with your hands.
Most clutch and brake lining rivets that I have seen on Brit vehicles are copper or some variation like bronze.
If you are concerned, look up on the internet for some specialty adhesive for brake and clutch linings, and use both adhesive and rivets.