GT40 oil pan hose washer cracked

While putting the drain hose back onto the oil pan during the GT40 rebuild, I over tightened the elbow connector that screws into the oil pan and cracked the hard plastic washer. The boat is sitting in the driveway while I work on the gelcoat and waiting to get the transmission put in. I've had some oily residue coming out of the hull drain port that I first thought was just from a dirty bilge, but I got in last night and discovered oil is leaking out of the oil pan at the drain hose elbow.

Does anyone know the specs on the plastic washer? Can I just take it to my local auto parts store and find something similar? I don't even see it listed on Skidim.

Thoughts?

So I found the oil hose kit on Nautique Parts and in the picture of the kit it showed a metal washer with a rubber inner ring. Went to the local auto parts store and we found a Dorman kit of 2 oil plug washer with integrated gasket. For anyone else looking its Dorman part 65274. Picture attached. Also...it can be found on Amazon but for 3 times the price as the local auto parts store!