No idea. But there are thousands of quality straps that will fit. Lots of makers use Buffalo skin. Any reason you want exactly the same for replacement? You might be able to get even better. just curious. looks like a stylized H, but it doesn’t look like Hirsch or Hadley Roma. Those are my only thoughts.
It looks to be the original leather strap fitted to the watch and rather than wear it out (its still in good condition) thought I might try and track down the original manufacturer and see if it was still an available strap. Emailed the watch manufacturer and asked them if they were still available but alas they no longer have them in stock (mid to late 90's watch) and not too much information available in their system to find out though some watch parts were still available for this model but this watch would have been a very low production run. The leather they used is very thick, most of my googling of buffalo straps so far turns up straps that are not as meaty as this one.