WICO series A mag - Distributor Cap for Twin

I seem to have lost the center pin off the spring out of the inside of my distributor cap, any ideas where to buy a new cap? or a new center pin? or what to make one out of ????

thanks

Ok, I have found a generic replacement bit of carbon on a spring for the cap,

So the question now becomes has anybody tried trimming carbon?
How best to do, saw, file, etc, assume it is going to be quite brittle
Thanks

Done it in the past with 240 grit emery paper. takes a while but not too long.

Thanks, ended up using a metal blade in hack saw to start, then finished and shaped with enery paper, works fine thankfully.