Versatility of the Hunting Sporran.

[Bugbear]

Glad you asked this question; I have read often that normally a metal cantle and fur or hair body are on a formal sporran.
Full mask sporrans are used with daywear, as well as, formal evening attire, I think.

However, I would like to know, from those who know, which sporrans on this page from the Scottish Tartans museum are formal. I think Matt newsom has said a couple are, and several seem to fit what you are describing.
Ferguson Britt Sporrans

I've been pondering the "Glengyle Fancy Fur" for a long time now, but it does not have a metal cantle. I think there was another on that page that has the same fur options.

And what about sterling silver bead work on a leather cantle, does that change it's status?