These are the screws that are for many loco's by Tri-ang /Hornby especially where the valve gear is in two pieces and fixes to wheel with a screw.
Hornby S1010 Valve Gear Screws [2( Long Shank Used But Good )
Hornby X7659 Valve Gear & Connecting Coupling Piston Rods For Class W1 Hush Hush
HORNBY X1475 VALVE GEAR LEFT SIDE SCHOOLS CLASS & D49 HUNT SPARES REPAIR NEW