Utilikilt snap extenders.

[Iolaus]

I dont think they would work too well. The purpose of the snaps in the UK is to both hold the material in place left and right, plus up and down. Unless the extender was stretched to the max (and just get a kilt that fits by then) the extenders would allow the aprons to 'sag' in relation to each other.

You'd probably be better off just putting some new snap bottoms in the correct place on the underapron resizing it that way.

I can think of a way to make it work; I'm just not too sure I'd like how it looked.

Sandwich some velcro between the inside corner of the under apron and the outer,and let the beltloops hold up the outer apron's corner and kilt-side edge of the inner; that would hold up the aprons, and the snap extenders would be there to hold it closed.

Of course, with the overlap of Utilikilts already pretty minimal, there wouldn't be much fabric left to protect your modesty.