Hunting for days trying to find the fasteners for my Mark V door moldings. For the Mark V saloon there should be 12. Found two, then remembered that I had broken off the rest of them taking the car apart all those years ago.
Just recording here for posterity, that the BD.125 bolt for the door moldings on Mark V is a slotted truss head 1/4-26 BSF x 1/2" long.
A truss head is like a satellite dish.
I got some 1/4-28 UNF slotted truss heads in stainless from McMaster-Carr. The heads were a bit too high, and the slots not quite wide enough. The bench grinder topped off the crowns, and the air die grinder with a 1/16" cutting wheel opened up the slots. Trial and error. By about the 10th one I was getting a good fit on the second trial.
Such a low part number made me think it was probably used on earlier models, and so it was; the '40-'48 saloon door mouldings. Possibly the DHCs as well, as the SPC mentions 12 Nuts on Tee Bolts for Door Mouldings, though the bolts themselves were included with the mouldings and are not listed separately.
Not used on the '38-'39s, they had screws and studs.