Chris
I was in the same position as you a few years ago when looking for a rack.
The original supplier (HoE) was out of stock , but John Worral advised me to try a couple of dealers , and sure enough Berrybrook had one , which they posted to me the next day.
Appreciate that you may be committed to Melvyn, but i would ring around and see if one can be obtained elsewhere , or try a different supplier altogether (Librands rather than the factory option)