Forgive me if this is stupid and way off the mark, but .......
... looking at the photos of your engine bay, if the chassis rails are the same between Mk 3 and Mk 5, could you not go to the local breakers, and get the two engine mount support brackets , from a Mk 3, and bolt them up to your chassis....?
I am just guessing, never having seen in a Mk 5, but then you could do the mod that 928 John did on his, to utilise the Granny mounts.....?
cheers.....




