saw a damaged breachblock today

I concur with the comments on the cause of the damage. This is one of the most common failures of Lugers made prior to about 1925-26. During that period firing pins began to be made with the gas bleeding flutes. Many of the Police used WWI era Lugers were later fitted with these type firing pins. If you look closly you can find examples of the original firing pins in many of these type (Police) Lugers that had the firing pins expertly arsenal (not factory) modified to the fluted style. IMO the fluted pin is a MUST have for any shooter Luger esp. if reloads are used.