The might both be covered by a plastic mesh filter.

IME there's two differing heights of plastic pipe on the tank side of the tap, the higher for normal and the lower for reserve. Maybe they've been reversed by a previous owner or removed altogether. Might be worth putting some fuel in and draining it out by turning the tap to normal and then see wha...

I find living on a small Scottish island very effective. If it did disappear then all I'd have to do is wait at the ferry terminal.

I'm the happy owner of a not yet delivered AR. It's working it's way slowly upcountry. Started of in Cumbria and should be in Glasgow by the end of the week and then over to me sometime next week.