I have a Casio BM-500W which has two stripped holes for the case back screws and also the gasket is deformed and hardened.
First question, what is the preferred method to use for stripped holes? Personally I am erring on the side of larger diameter self tappers, not had much luck with filling the holes, but how large should the diameter of the new screws be to make a solid bite into the case.
The specs of the current screws are as follows:
Max thread diameter: 1.33mm
Thread length: 4.83mm

Secondly, the gasket, which is unique and not circular/oval, needs replacing and the chances of finding an original in good condition are slim. Therefore, are there any magical products out there to create a new seal.
In the past I have used automotive liquid gasket, which has worked well, but is there anything else?
You can see the gasket in the following link: mircogarau: Orologio CASIO BM-500W (943) weather station barometer altitud Watch LCD vintage

Cheers,
Tom.