It’s been about 5 years ago I was able to order the oil pump rebuild gaskets separately. The oil pump mounting gasket, the o ring gasket that goes under the rotor plate, the small gasket that goes into the relief valve end plug.
Give me a day or so and I will look in my parts manual and get the part numbers.
Another place to look and do a search is on e bay, from time to time nos rebuild kits that include the inner and outer rotors and the gaskets are posted for sale.
Also look on Rock Auto, they may have the individual gaskets for the oil pump.