I'm thinking of doing away with the original side-safety trigger on my Parker Hale 1200 and replacing it with a Timney trigger without safety. So, I'll need a safety on the bolt. I'm not into the 3-position Winchester type safety. I prefer the Buehler style and I can easily install one on a standard military Mauser bolt shroud.

Can I replace the bolt shroud, firing pin, and firing pin spring on the Parker Hale 1200 with those from a military Mauser or are they non-compatible?

Yes they are

All you need is the shroud and swing safety.

The Parker hale is a Spanish Santa Barbra 98 action . Any 98 should fit . I say should as some ph98s bolts are made in 3 parts ,and I've had issues with the cocking cam area being a little large . Easily remedied but just be aware . I've got a few hundred new fn shrouds and none that I tried would fit one Canadian M-82 PH bolt .
Good luck
No I'm not selling the parts yet .