I suspect you have been unnecessarily cautioned about alleged fragility of 1892 bolts. There is likely no significant difference in materials or manufacture methods between the earliest and latest US Krag bolts. All can be damaged by excessive pressure and all are entirely adequate with normal-pressure ammunition.

My advice: examine your 1892's bolt carefully for cracks; if none are found, use it when firing your 1892 Krag; stop worrying about headspace because it's not a common problem with US Krags.