Certainly worth a crack. I've spent more on less I am sure. A 20 E could be a spectacular piece. Fwiw I have owned 7 Lefever arms 20 ga guns and 6 of the 7 had "bad barrels." 4 with barrel walls .010 to .018, one with a hairline crack and one with bulges. 4 were fluid and 2 were Damascus. The 7th I have yet to measure as it sits in the safe likely unfired and I am not sure I want to know.
( I am clearly a sucker for a Lefever )