I took a closeup of a substation this weekend and noticed that it used a set of multiparts on the outgoing 2400V delta circuit, and as each one is different, I have reason to believe this was a deliberate choice by some long-ago lineman. I'd like some reasonable estimation as to the M-numbers represented. I know the left (and likely 2nd from right) are Westinghouse, and the one on the right is clearly Ohio Brass.