Help w/1903 Mark 1 bolt

I just acquired a nice Springfield Mk1. The rifle came from a vet who claimed he had the rifle during his stint in the Army during WW11. The serial number coincides with the barrel date of 2-20, so the receiver/barrel combo seems original. The muzzle erosion is barely over 0. Great find. A few of the parts have been changed, the cut off switch and the butt plate for sure. The stock has a P in a circle, but no cartouche, so unsure if stock is original. I'm confused about the bolt. It is the straight as opposed to the sweeping bolt handle. The only proof marks are the three hash marks, or three 1's on the bottom of the safety lug, which represents an early non double heat treated bolt? There is also an R underneath the bolt sleeve. However, on the underside of the bolt is a punch mark and a faint number. If I truly have a non double heat treated bolt, is it safe to shoot?

my Remington m1903s as well as an A3 have that punch mark under the handle, with an R stamp. Before zooming in on your picture, it looked to me like the other mark under your handle was a faintly stamped "R". After zooming in I wasn't as sure.
Here is a picture of Springfield bolts
Attachment 114532
Here is a picture of Remington m1903 and a3 bolts.
Attachment 114533
Photo's courtesy of vishooter.net. As you can see the "swept" Remington bolt is more straight along the entire handle, but pointing slightly to the rear. The Springfield swept bolt has a little flare at the end.
I would lean toward you having a Remington M1903 bolt. If I'm wrong, then an expert will be along shortly to politely correct me.