Michael, the little bolt detent is a perfect example of the things I find most interesting. Installing a detent on a Mauser bolt is easy, the Oberndorf factory showed us how in at least 2 different ways, but the 1903 has always been a puzzlement to me. Some other areas of interest include a trigger-block safety and the details of its retention & positioning, and a closeup view of a Shelhamer grip strap. I'm not interested in using that feature myself but would like to be able to determine the authenticity of any purported Shelhamer stock that I may encounter. Bench-made peep sights of the Krag/Rice type or the one you showed recently on a 1903 would also be quite interesting to me, as would any tang safeties or other unusual alteratioms for scope use.
Again, thanks much for your efforts, they are appreciated! Regards, Joe