would I use it?
Absolutely! I wouldn't change it any at all, because it is a family heirloom. If it was just a mauser you bought, I'd suggest altering the bolt, then drilling and tapping for a scope, in order to take full advantage of a great rifle's abilities. But, since it was your grandfather's... keep it just the way it is.
Mausers are GREAT rifles. My deer rifle is a Swedish mauser, and my elk gun (if I ever get to go) is an Argentine mauser rechambered in .35 Whelen.
I always felt that if I got to the point where I thought it was time to bury my firearms, it was actually time to pick them up..