This is an old thread but I thought I'd add some pictures of the changes I made during the build of my 4 Star. I know there are a lot of modified Sigs out there but not many pictures of the mods in progress.

So, first of all you start with a frighteningly clean workshop and a box of bits!!


There's a lot of information out there concerning Sig Mods so, after deciding what changes I was going to make, I amended a copy of the manual to make sure I did things in the correct order.