On V-504, I have two valve covers on each side of engine. They have a sound deadening "feature", but engine would be much more reliable without it, at least if we are considering age (not running hours). Instead of being made whole of aluminum, each cover has rubber insert approximately in the middle so that it acts like absorber (aluminum next to the gasket on engine, then about 10cm(4 inches) above, 1cm (1/2 inch) rubber is all around and the top of cover above that rubber is again aluminum). The problem is that the rubber is old and the leaks are showing on some points where rubber connects to the aluminum. So here are a couple of questions:

What would be the best soluton:
1. Welding it to be whole aluminum? If welding, I am afraid that the cover will maybe bend so that it will not seal well with the gasket.
2. Using some kind of liquid (epoxy) metal to seal the leaks (i.e. Loctite or something similar)? This is probably the lowest quality solution.
3. Finding/shopping covers without rubber absorber? Probably the best solution, but finding them will take quite time since it is an old type of engine.

If there is any other advice, I would like to hear it.