When I bought my Tilly back in 1989 it came with an original tilt, but the top (Bren gun) panel had been replaced with a totally different colour canvas. So I bought a new one off the Worthing's, which was just a tilt with no windows or panels. They also made me a rad muff. But then they gave up on British stuff to concentrate solely on US vehicles.
Some years later when Allied forces started up, I gave my original tilt to Jim to hopefully find a suitable piece of canvas to replace my top panel, which he eventually did after about 3 years. I think he used it as a pattern to make some tilts and he also borrowed my rad muff to copy.
Sadly since Martyn retired and left Jim on his own, I think he also concentrates on just US vehicles. But worth a call I would think and maybe mention my name. Ron Pier