Short Shift, DIY job?

Guys, I've found old posts on short shift fitting etc, but as nobody seems to be able to supply the shortened part required, is there a guide on how to modify the part? It would seem to be a case of shortening the part and re-welding, but how much would it need to be shortened by and and which particular part of the linkage etc?

Cheers

G

PM Ross (H2ypr) - he was offering these a few months ago.

Cheers MABR