Threaded holes in M1870 triggerguard plate?

[Hammer]

I corresponded with Dick Hosmer about this and he said he’s never seen these type threaded holes in this location before. He validated that this trigger guard is on a legit Type 1 version of the M1870.

Trying to figure out if these holes may have been for some type of pistol grip attachment.

[John S.]

Sometimes addition of set trigger parts added screw holes in the trigger guard strap, but there would have been some added inletting in the wood behind it to accommodate them.

Or, maybe it was for addition of some sort of spur or rest or grip to suit an individual's taste.

I would bet that it was NOT armory work, or even done while in service at the unit level.
All strictly guesses and you are free to agree or not.

[Hammer]

Sometimes addition of set trigger parts added screw holes in the trigger guard strap, but there would have been some added inletting in the wood behind it to accommodate them.

Or, maybe it was for addition of some sort of spur or rest or grip to suit an individual's taste.

I would bet that it was NOT armory work, or even done while in service at the unit level.
All strictly guesses and you are free to agree or not.

John, your guesses are 99% more qualified than my speculations...

And since Dick said he hadn’t seen something like this before either, it is likely that these may not have been done by the military.

I’ll need to decide now if I should replace this trigger plate with one that does not have these drilled and tapped holes in it, and If I do I’ll keep this trigger plate with the rifle as part of its history.

[Tony Beck]

Quick way to tell if they are armory, are the threads #10, 11 or 12-26? Springfield liked 26 TPI, but it is decidedly non-standard today. Internal lock screw are #10, The lock plate through the stock screws are #11 (0.2" diameter) and the barrel tang screw is #12. Try threading one of those screws into the plate. Don't force it if it doesn't want to go. Also, the thread angle is 55 degrees instead of today's 60 degrees, but modern threads will fit with a little drag.