Yes, the bolt body has the R and all my parts have the R of Remington. Yes I have a nearly new 1903 A3 Remington and a copy A3 bolt body (poorly forged A4) acquired to test my M1903 A4. I acquired the M1903 A3 for my collection and to make another one for the A4. I checked the headspace and indeed, it is not good with the A4 slide but OK with the A3 slide. At first, I thought the chamber was HS but if the bolt body is OK...! I have no more doubts. I have to find an original A4 slide.

If all members who own A4s can photograph their original slide, cocking lever side, we will certainly have 2 models. One bent towards the rear (like me for an A4 model of the first series), another straight (ease of construction for the other series?).