I love how this whole thread basically flies in the face of the SCA "take a knee" approach to limb loss.

It would be a little unwieldy, but you could try rigging up a thicker peg. Make it out of something lightweight like aluminum, then cover it in wood veneer. They make wooden tubes that would be perfect for this purpose: http://www.lenderink.com/products/wood-tubes/. Maybe you could even paint it in a good heraldic fashion. Or, if you can handle the weight, make it out of actual wood (basswood is probably best. Decent durability to weight ratio). Point is, a thicker peg would give you a wider surface area, a decent pivot point, and a makeshift club in case you get disarmed.

This will help even though this man is not a full leg amputee.
https://www.alamy.com/stock-photo-slovenia-cristoglie-hrastovlje-the-romanic-church-of-the-holy-trinity-88574889.
htmlrastovlje, Church of the Holy Trinity, Slovenia