The next step was to make the Trigger Pin Cover, and this was made using a small piece of brass sheet and holding it in two pairs of pliers, after cutting to shape, and then bending over the round edge until it is almost 40deg. The edge to be soldered to the housing was then filed flat with a small file and test fitted to make sure that it sat nicely.
I then floaded the area with solder and ground it all smooth with my mini Dremel tool using a cut-off wheel.