Brass Cantled Sporrans - Need Historical Guidance

[artificer]

Howdy all,
I have lately been deep in conversation with a metalsmith buddy of mine. I've been steering him toward the idea of making some brass cantles for me in his down time.

I've obviously done the basic forum search here, and amongst the online musuem images out of Scotland to help inspire (as I'd like it to be an historically inspired design).

I am trying to narrow it down to a few basic designs to do some trials on.

The one I've seen the most is the basic brass "half-circle" purse mouth, which utilizes a pierced bottom for lacing the bag on (or alternately a threaded-post back, but we've decided to steer away from that for now).

From what I've seen this bag is usually seen with small etching, plain fronted, or with a pierced design.
From the Glasgow Museum Collection

This is the style I'll most likely have my friend make.

The second I've seen is the 'stepped' or 1/2 hexagon top profile. I've only seen this the MacLeay illustrations (if I recall correctly the source), but it appears to have more 'relief' than the 1/2 circle, with repousse or other type of embossed detail.

The third type I THINK I've seen (if I'm interpreting the illustrations correctly) is basically just a brass plate (presumably with a matching back plate) and no metal 'hinge'. It just laces onto the basic leather 'purse' to add stiffness and decoration to the mouth of the bag.

So, to all you historical Highland dress experts out there, is there anything in my ( very simplified) description that strikes you as 'off-target'?

I'm sure there's a TON of stuff out there that isn't online, if anyone has extra info they'd care to share, I'd be most appreciative.

Thanks in advance.