Car appreciation... the aesthetics, the engineering, etc

They're pretty, but those ones clog quite easily. A friend had one on his car, got a bad batch of petrol with a fine pink grit in it, and we had to stop to flush the filter about once every 20 miles until we could flush the tank. I recall he disposed of the contaminated petrol down rabbit holes at a campsite at the Le Mans circuit. Maison Blanche, I think.

Have you tested the fuel pump? Now you have the glass filter fitted, try running the engine at 2.5/3k and watch the filter to see if the fuel empties faster than it is replenished.

As an aside, it is best not to use jubilee type clips on fuel hoses. The 'plain' silver clips you have connecting the hose to the hard lines are proper fuel line clips which apply equal pressure around the circumference and don't crimp the line.

I had a recurring issue very similar on my Elan. It took ages to find the problem but it turned out to be a very small kink in the fuel line under the tank. It was just enough to restrict fuel enough to cause it to die as soon as it got hot enough.