Conversion gasket kit queries

Got two 2L blocks with oil pumps - both had a gasket between oil pump body & u/side of block.
I purchased a bottom end gasket kit & it doesn't have this gasket.
Supplier says there is no such gasket in kits (no's 850 or 860)
Anyone shed any light on this?
Also kit has a nylon washer/spacer od 22, id 14.5 & 2mm thick. What's that for?
Thanks, Gregg
I purchased a bottom end gasket kit & it doesn't have this gasket.
Supplier says there is no such gasket in kits (no's 850 or 860)

Anyone shed any light on this?
Also kit has a nylon washer/spacer od 22, id 14.5 & 2mm thick. What's that for?
Thanks, Gregg