Frank - you could replace the end cover with a slightly longer length of fuel pipe and slot it over the protruding catch. I fabricated an aluminium fork on my home made stays for the very reason you mention. I once had the wind lift my MGB bonnet, which was held open by a chromed steel tube on the centre catch. The tube fell to the offside. The bonnet didn't drop because it had a side support, but the tube dropped across the front wing and made a very very slight indentation. Since it was white, it didn't show, but I knew it was there...........
I would drill the front bracket and use a small nut & bolt, or pop rivet. You might also consider sourcing a different fastener. There's a company (advertises in Practical Classics) which specialises in small clips and fittings.
These bespoke stays don't fit the Series1 Roadster on the nearside because of the large intake trumpet being in the way so it won't fold down.
