Plastic washer identification

[hotponyshoes]

The kit instructions show the part number to be #890968 and call those plastic parts nylon washers. Washers for the tiller right? So likely fine to just use a nylon washer of correct size, or modify nylon washer to size - or contact seastar and see if they sell the part individually outside of the kit

For instance, https://www.igus.co.uk/product/132?artNr=XTM-2238-015
You can get close to your required size on this and a little bit of modification.

I tried uk seastar first but they only get them in as complete kits from the US.
They did helpfully explain that the kits were expensive as they had 2 stainless steel bits in as well...

I'm sure a plain nylon washer would be fine, I haven't actually tried searching for nylon washers in that size so might be a good starting point!