FWIW, the plastic version I made earlier in the week which was installed with a tiny bit of preload had distorted enough to have no preload 48 hours later when I replaced it with this version last night
This is the final version which is being prototyped in aluminium next week. Expect a purchase price of £30 per unit inc UK shipping.
There's a slight gap at the top right because the bar isn't actually parallel - it tapers slightly towards the strut top. The block is a snug clearance fit on the bar though, and has 0.5mm preload.
This is the best I can do regarding the cover. It mostly fits, but to achieve any more clearance would compromise the strength of the block and therefore its function.
The cover may sit further down with some trimming around this area
