Dave
Excellent post, I will have a go at this, additionally I want to look at the difficulty of a sump guard option in light of Frank's incident.
After posting my first comment this morning. I would never have thought of an under tray, but thinking on from there, Would a deep fabricated 'traingle cross section' of thick 'Ally' with a couple of tie braces, set across where Dave has the back of his undertray, have prevented hitting my sump because I'd have hit that first.