GB Coureur brakes

I have a set of early 1950s GB Coureur brakes and the blocks are shot. I could not find any block sizing info and the old ones seem to have been carved out of all sorts. I intend to use Fiamme sprint rims which have quite a radiused braking surface and have been looking at Kool Stops range of salmon coloured pads. After a bit of a rummage through the junk box, I found a Fibrax pad marked 284 GB No. 35W. These are the correct fit and length for the original pad holders. They are just over 38mm long and the dovetail is roughly 10mm x 9mm. The only Kool Stop of that size is the Mafac 4 dot replacement but it is 46mm long. I would have to cut half a dot from the length. The solid Campy ones would be better to cut down at 40mm but the 12mm dovetail will not go in. Does anyone have any better ideas? Am I better off changing the complete pad and holders or are there alternative quality pads available? I would rather the brakes worked reasonably! It is not an area I particularly want to bodge for safety's sake.

Cheers - Chris.

Re:

Ok. After a bit of hunting around, I decided to try Kool Stops Mafac four dot pad as it was the closest size. They just dropped into the holders so the correct size is pretty specific. However. The holders being thin aluminium were very easily adjusted to a good tight fit. I did this by fitting the new block and supporting the holder on its bottom tab on a steel block and gave the top tab a few light taps with a good flat faced hammer. This bends the tabs tighter onto the narrow section of the blocks dovetail.