UK Pete -
Steve Swan wrote in earlier discussion-
"Case, oil filter, vin 1 - 4148, pn 15411-300-000, Smooth exterior, no fins
Case, oil filter, vin 4149 - 7414, pn 15411-300-010, External cooling fins added
Case, oil filter, vin 1 - 7414, pn 15411-300-010, Internal strengthening ribs, added to finned oil bowl, number "2" on outside - Honda supercession, 26 Jan 1970" copied from Steve Swan post
The smooth ferrule webbed fabric oil line stopped really close to vin 4148 but I don't know the exact vin number the change occurred. I own vin 4089 and it was fitted from the factory with smooth ferrule webbed fabric oil lines.
Best,
DW