I don't like lamp irons. They're a fiddly detail that I never take any notice on on real trains and couldn't really care about on models.
7mm trains really need more detail than 4mm ones (Yes, I know that 4mm ones get lamp irons but only if I don't think I can get away with it. Stop being picky) and so somewhere to hang your lamp is a necessity.
2 sizes are supplied in the kit. After a bit of thinking, I realised that the longer ones were intended for the middle top position where there is a handy locating hole for the extra tongue to poke through. All are bent up in the same way although I think the half-etched lines are on the wrong side. Not that it matter if you take a moment to look at a picture of the real thing.
Fixing is a messy job with a conventional iron so out comes the RSU. The parts are tinned on the back and zapped into place with a dose of Resistance juice. No cleaning up afterwards and a good deal less bad language make the tool worth every penny.
This is fine for the side irons but by the time I'd tinned the middles, the tongue wouldn't got through the hole. So I cut it off and soldered the same way. Well, it saved me cleaning up the excess metal inside the cab didn't it?