Rotor Arm Hell

[halfnelson]

I'm trying to source a rotor arm for my 240 Torslanda, straight forward B200F engine and it's turning into nightmare.
Ordered parts for my annual service. Distributor cap, leads, plugs all OK, rotor arm wouldn't fit distributor shaft, wrong size.
Second try, right part number, ended up with the weird shaped rev-limiter type.
Third one turned up broken in post.
4th try - looked exactly right, same part number, except the small 1.5 on original and 2.5 on new one... car won't run with new one.
5th try... empty box turned up in post.
Aaaarggh! Getting desperate as the old rotor arm is now a few months past when it should have been changed and car starting to run rough.
Images below of the two types I actually have - original and non running replacement. Is there a resistor in the arm? Where can I get an original? Part number 1234332350.