Looks like the ones made for 'Classic Old West Styles'.
'The Fort' - in Lincoln, Nebraska, has some still - you can call them toll-free at - 1-877-907-3678 - X199 - or email them at terrylane@fortoutfitter.com.
Ask for Terry or Glen.
As an aside - matched gunleather was quite uncommon during the period.
This allows you a very wide choice, should you so desire...
Vaya,
Scouts Out!