short version: Striped the plastic drain valve on a CSF 2670 2-row radiator. Can anyone confirm thread size or a replacement part?

long version:
Stuck my hand up in the Jeep to tame the fan shroud rattle and made contact with the plastic drain plug on my radiator. Drain plug got to drainin' so I twisted it tighter. That made it worse. The thread seems to match M10-1.5 thread, but it also goes into M10-1.25 pretty well. The threads are pretty mangled, so it's hard to tell. I'll hit up the hardware store tomorrow to buy some test-bolts while I try to figure this out.

Also, I don't even use the drain plug! Lower radiator hose?!

 

I have a CSF 2671 3 row buried in the shed..if the drain plug is undamaged will ship it to you...wont get to it till monday. Cant believe they are different