As mentioned by jimster in this thread: viewtopic.php?f=59&t=8000&p=53307#p53307
You can contact WatchObsession and they had Hirsch do a one off special order for you.
Another option would be 26mm Morellato Flat Unstitched Leather strap, but its non-taper and 26mm all the way. I have 2 of them for my Kappa and they are decent quality for the price.
Nice pick up btw, post a few photo and what you think about the watch if you have a chance.