37-39 instrument question

[gkgeiger]

I needed a temp gauge for my 39 and ended up buying a really nice complete set of 37 gauges. I'm in the process of changing them but ran into a small issue. My stock 39 ammeter has a metal bar running from a common positive terminal. My new 37 gauge doesn't have a threaded post but something different (see attached picture). I'm assuming I just make a jumper wire but have no idea what kind of terminal/connector to use on the gauge end. Does anyone have any help? Thanks in advance
37 ammeter

39 gauges