Thanks for chiming in, Jim. I considered the possibility and found one solution here (https://www.talkbass.com/threads/hea...2-etc.1304234/). Thinking that a little untidy for this build, I've been keeping an eye out for similar strap extension bracket solutions. In Supercheap Auto this week I happened to spy this mini hacksaw with a difference. I've only ever seen these with a moulded plastic handle, but here is the same tool with two metal side casings and a plastic filler. It dawned on me that ripping out the rivets would leave me with a suitably shaped bracket and the crease/dog-leg in the middle would conveniently allow one (the skinny) end to be inset into the neck heel and subsequently buried within the neck-body mounting. The exposed piece could use some shaping, depending on its strength. The whole tool is quite lightweight and possibly aluminium, so I wouldn't want to weaken/reduce it too much if that's so. Will see what I find when I deconstruct. I'm seriously going to consider this. Nothing lost if this $12 trial feels too flimsy, will keep my eye out for alternative solutions.
Edited: Good news is, though light, the metal is pleasantly stiff and will be suitable for purpose I believe. In 3rd pic I've marked a rough idea of how I'll shape the extension.
Peter