Faced with their imminent extinction 
and if no pattern part emerges to fill the void, can more frequent oil changes be enough to cope with not having one at all?
I suspect it's needed as all cars have them as well as an oil filter- if you have debris in the gearbox for instance (where engine/gearbox share the same oil) it's going to drop into the sump and get sucked into the pick up so a strainer is essential in my view to keep out large bits of metal or rubber etc.
In the complete absence of a replacement I guess it will be a case of adapting one from another engine and joining it to the same end fitting.
