Big enough trigger guards, and you don't need to swing it down to make room for your thick thermal gloves to get to the trigger isntead.

Plus, if you do need to pivot the guard open, then you don't want it pivoting forward, but to the rear as normal instead.  Hence you never going to feel it under your thick thermal mittens with gloves under them, and with it pivot forward, just gets in the way for mag changes isntead.

Trust me, until is cold enough out side that any exposed skin will frost bite in a mater of mins, where you are not only wearing thermal gloves, but mittens over the top of them to keep your fingers from frost biting as well, no reason to even think about swinging a trigger guard down instead.

If you just want detent pins on the back, easy enough to do the mod.
Think watch band detent pin, and easy enough to do with some drill rod to make the end pins and a spring in the middle of them.



If you want to go screws, then easy enough to do as well.
http://www.ebay.com/itm/10-Sets-Magpul-Aluminum-Enhanced-Trigger-Guard-Installation-Upgrade-Screw-Kit-/140915999430


As for the roll pin, if you just bevel the ends of it, and have the correct back set plate, then installing and removing the roll pin for the trigger guard is a snap.

Hence just chuck the pin up in a drill to spin file the end of the pin to bevel it both sides, hit it with some cold bluing, and it will punch in and out of the receiver without problems/fear of cracking a ear with a punch and punch block.