I am attaching a riveted aluminum aventail from Ice Falcon to a klappvisor helmet. I am trying to figure out what gauge of leather would be best to support it from. I believe the weight is about 2-2.5 lbs.

Any advice would be apperciated! :D

2 to 4 ounce leather (veg tanned) would be plenty strong and still provide flexibilty. Staining, or dyeing, the leather would increase its stiffness (slightly), so I wouldn't be thinking of a much heavier leather.

Hope this helps.

I'd definitely go with the 4oz rather than 2oz. I used 1.5 mm (4oz) veg tanned leather to attach a butted spring steel aventail (3.5 kg / 7.7lb) to my bascinet.

I cut a long, straight strip twice as wide as I needed plus about 4 mm then folded it in half, wet it and formed it to the helm up the sides of the face opening, punching holes as I went to go over the vervelles. Let it dry, then dye it if you want then - and this is critical - grease the hell out of it. I used tallow, but dubbin will do. Use a hair dryer to gently melt the grease in. Leather can be a real moisture-magnet so greasing it is important.

Once it was formed I inserted the aventail half a link in and and sewed it together. It really helps to tack the ends in place, then the centre-back, then arrange the aventail and tack it in place every couple of inches or so before sewing the whole thing.

Hope this helps. Unfortunately I no longer have the helm in question so I can't take pictures.