Parts can be had:
http://www.wisnersinc.com/rifles/remington/boltCF.html
And Gun Parts Corp. (Numerich), has been making new M788 magazines for several years.
I have four of them, two in 22-250. Both of which will shoot three shot groups almost touching, with 55gr Btip loads. The one in 222 will shoot almost any load into less than an inch.
The one in 243 is almost as accurate with 55gr Btip loads, likes 100gr loads even better.
BTW, broke the bolt stop in the first 22-250 I ever owned (1978), years ago. Since it likes them Btips seated out close to the lands and they won't fit in the magazine, just use it as a single shot for woodchucks. Never did bother to replace the bolt stop.
Replaced the bolt stop in a relative's M788 last year. Main reason they break, is because the bolt will slam back against them if ya ain't careful when ya pick them up with the bolt partially open and no rounds in the magazines.
Since they have rear locking lugs, nothing to stop the bolt when it slides back, but that little pin.