Flat faced hydraulic couplers

Anyone know where to get the seals/o-rings inside the flat faced skid steer style couplers?

Local dealer did not have a breakdown of the coupler and could not match up the seal/o-ring needed. They just want to sell the whole coupler. Coupler is specific one that mounts to the skid steer and is rather expensive.

Thanks for any suggestions.

Flat faced hydraulic couplers