The velour that I have doesn't stretch as much as the cheaper velour that is sold in standard fabric shops. That version of velour is designed more for clothing and requires a lighter weight an more flexibilty. However, that variation is made from a knit fabric. When you cut out the pieces and attempt to sew them together, the knit backing tends to shred quite a bit of the strings that hold it all together. This is why I chose to move towards the upholstery grade version. It is denser, but doesn't shed nearly to the degree of the lighter weight material.
But, your thought is a great one. Since the use of the spray adhesive would be used, then the lighter velour would have more flexibilty and since one would not be stitching it, then it would stay together relatively well.
I did get 4 pair of the Sennheiser 414 pads yesterday. I'll get the reverse quarter mod performed and check into applying some of my velour to the pads in the next 3-4 days. I have the L-Cush pads, but not any spares to sacrifice at this point.
Full of good ideas, I am ;)