Help! Starter piece broken?

Alright, I pulled my starter today, as it was on its last leg. My buddy had a grand that was trashed because of his wheeling, and they parted it out last week. I got his newish starter, about 20 starts on it or so. and as I was bolting it up, I noticed this hole. The little plastic part was somehow pushed in, probably from being placed down on a table. Should I open up the new starter and look for the other little part of the plastic piece? Should I leave it as is, with a big hole (I don't think I hsould do this) Should I take apart the top of both starters and switch the old but still intact piece over to the new one? Help cause My jeep is dead in the driveway right now.

Old starter piece

New starter

broken piece.

yes switch the plug from the old starter to the new starter u dont want debris getting in there.

I took the old starter's top off, and I took out that piece, I decided I didn't want to take the new starter's top off because after looking at the old one, there are spring loaded pieces that wouldn't allow me to put the old top back on. The new one's screws probably would have been easier to get off to fix ths problem, but I didn't want to test my luck

So I took the old plug and put it into the hole of the new one, only reversed.

The holes are to hold the brush springs while you put it together.