British hardware nomenclature translation

I made a post this morning inquiring abuut hardware needed to mount the grab handle BD 24922 on a 1967 E type, I subsequently found a parts list which says I need qty 4 DAZ004/10c , and 4 BD 532/1 washers as we// as 2 DAC 908/12 C screws. If I just knew the description: diameter, thread size, type of screw (machine or sheetmetal) and length I am confident I can find something to work. It looks to me like the uppermost (top) piece is the black vinyl covered triangular [piece, Two screws seem to go through that piece and through the chrome piece into the A pillar cover, Is it just those two screws holding this sandwich together? I called SNG Barratt and they said they do not stock those parts and do not know what they are because Jaguar never identified them. (Ahem!) Thanks, Mike Moore

This is the fastener decoder I use, supplied by a helpful contributor here in the past:

Mike, it’s put together exactly as you describe …. The screw are self tapers per the listing from David …. And are chrome plated…me i just use raised head countersunk stainless ( I polish the ends first) ……no one ever looks there anyway!