[MattW]

Firstly looking at the replacement arm, it does look like an Orion/Peak arm to me. It's hard to tell from the comm end only!!

It's a tough call really. Personally i think i'd just run it and be happy, but it's your call.

If i was looking at the origional, and was an importer, i'd probably note that it looks to have had a fair bit of running - looking at Comm diameter - again hard to tell from a pic!! The other big question that i would be asking, is how did it get rusty?? usually caused by water being where it shouldn't be..........

The cause of many motor failures is that they have got too hot. If they get too hot and do some damage, they may well still "run" just not properly. I know in touring cars it can be an issue: get motor too hot and they go out of balance. When running out of balence, epoxy putty often comes off which leaves them more out of balence. If still run, the wire will probably ultimately snap and smash into the maget and create a large mess/paper weight!!!!

The motors with the groove in them are especially hard to gear, and 10 turns even more so due to the arm blank that they are wound on.