1903 tg

When were the early 1903 triggerguards modified with the pin? These were only used on rebuilds and not original production, correct?

Ferris & Beard write in their "Springfield Model 1903 Service Rifle Production & Alteration 1905-1910" that the problem began in 1905 production but wasn't discovered until late 1905 or early 1906 when the parts produced in 1905 were assembled into rifles. Pinning the TG began in 1906 and continued until ~1910. So the pinned TGs were apparently used in new production (assembly of rifles from parts) through to the last alterations of the rod bayonet & 1905 modifications.

Thanks for the detailed answer.