I've gone for the "Superleggera" look, tread rubbers gone and 4mm s/s button heads with 2 nylon washers, 1 s/s washer and 1 nyloc nut to fill the 18 holes. I think i like it but i need to live with it a while. As a back up i've ordered a 6 ft length of Woolies best 7/8" tred rubber to make 2 replacement rubbers complete with end covers if i decide to revert to "trad", about £20. I'll need to drill the ali tread rail so that will allow me to select what fixings are best suited, countersunk maybe, but will keep the nylon washers to install under the rail so as to keep the ali rail from indenting the paintwork which is fortunatly still intact on my 2011 car.
A nice little winter project together with the braking system pipework change out to brass fittings and cunifer tube, car doesn't actually need it but it does look nice when its done and is maybe a plus when i decide to part with it.....Oh dear will we ever grow up and stop tinkering with toys!