Naturally, a former extractor gun that was refitted for ejectors at a later date would have to have the frame machined to install the in-frame ejector levers. Evidence of this can sometimes be seen when the machining removes part of the serial number or grade that was stamped into the water table. I don't know that anyone could say for certain whether your gun had been returned to have ejectors installed. I couldn't make out the first digit in the serial number on the left barrel, and that 5 near the forend hanger is very odd.
I've wondered whether at least some of these DS guns with H grade characteristics were early prototypes for a lower grade gun. It is claimed that Dan Lefever and the Durstons had disagreements over the introduction of the cheaper DS and I grades, and those disagreements may have been part of the reason for his departure from his own company in 1902. A lower percentage of DS grade guns had ejectors because the DS grade was built to a price point as a more affordable field grade gun. Ejectors are much less common in I grades, but a few are known to exist.
