Valkenburg/Castleford style caliga step by step

[Martin Moser]

Personally I think ALL Caligae stretched out in the back eventually.
also the ones found.

To a certain degree, yes, I would agree. This can be countered by making the back of the caliga a bit narrower/shorter at the heel than needed.
As can be seen in the last of the pictures of your caligae, btw., having the upper, horizontal straps too long also results in sagging of the heel area. The upper has slided down so that the ankle bone is covered, where those straps should clearly be above it. This then results in the lower back of the caliga bulging out to the back and the sides (as there is a surplus of material there now), even without the leather stretching. Looks exactly like the caligae of a friend of mine.

http://198.144.2.125/Roman/Full/caligae.jpg (a pattern for you)

Thanks, Marcus, the more the better. Probably the most widely used pattern in my experience. (Note, however, that this is not supported by any finds AFAIK.)