Hi Simon
When working with the N-Brass lamp irons, I try and get them in a vice or strong pair of flat nose pliers, I get them into position and then hold tight, and at the same time bending the bit required to form the L shape. After a bit of practise I can just about do it most of the time, did take practise though.
In terms of getting rid of the bits of flash I do that under a magnifying glass with a brand new scalpel blade, before I carry out the bending process.
First couple of times I used the N-Brass lamp irons I got the same effect, looked pretty much OK until observed under harsh photography conditions.
Also somebody does nice brass oval shaped buffers that suit the 4MT just lovely. Can't for the life of me remember, but they were an improvement on the standard offering. Well worth it.
Tihink it was someone via the NGS shop actually, I believe you recently joined?