Various dovetails of foresight elements, what do I have?

Ahead of changing the foresight element on the BSA 1945 T rifle mentioned in a previous post, I went to the references (Laidler, Reynolds and Stratton) and sorted my elements by type of Mark. I have 2 styles of Mk I, some Mk I*, some Mk II and a very few Mk III elements. There some I've called Mk Is with a vertical rear face of the base where the Mk I has a forward sloping rear face.

What I was not expecting was to find an equal quantity of similar but different elements. If the dovetail base on a typical No.4's sight is about 3/16th of an inch tall, what are the ones I've got with dovetails only about 3/32nds of an inch? Quite noticeably shorter, and all seem to have the transverse slot like the Mk I* and Mk III. Are these for the No.1 rifle or possibly CNo.7? My father had a lot of time behind the butt of a CNo.7 and could have picked up spares - as everyone seemed to do.

I'm curious if the split dovetails that are 3/32nds are Bren front sight blades? Do you have a picture to share?

I may have answered my own question again. The short dovetail and square relief cut in the photos are identical.

2: BLADE, foresight, Mks. 1,2, 3 - BRP CORP

Yep, that's Bren.

If you want to eliminate confusion, order one of Skennerton's Small Arms ID Series booklets on the No.4. (SAIS #2). They are cheap and have the real British Illustrated Parts catalogue inside. It has all the different front sight blades for the No.4 listed.