Ok so in a late night shopping frenzy I ordered late ball joints and lock pins (my car is a 74) but after buying 71 911T front struts (pinch style) I realized they use the early ball joint.

I know....dumb move.

The early strut still fits over the late ball joint and I can thread an M10 bolt through the pinch bolt hole. Is it considered safe/acceptable to use this combination? Obviously the wedge style lock pin doesn't work. (or does it???)

No. You need the correct ball joints.

Mark is right. You should not have any trouble selling the late ball joints.
As a side note, I wondered why not drill out the thread portion and put a wedge pin in place of the M10x30 bolt. I think it might be something to play with BUT NOT with a good strut.

The wedge pin is tapered, so I don't think you could just drill it out. I think it's smaller diameter than the pinch bolts

Ok thanks.
I also ordered the correct ball joint installation socket.