Looks pretty good to me !!
Well you made it work, so all's well that ends well..sometimes.
Was the original made of ABS plastic? Why do suppose it was "crumbling at the rivets"? Travel-rattle perhaps? ABS lip repair is very do-able and an example (not on refer flue) is highlighted somewhere on this forum IIRC.
Did you discard the old flue?
I am curious whether you ordered your part model specific to your AS.
That is did Inland ask for your particulars?
Did Inland inform you that the part might not fit your particular year and floorplan model exactly?
or did they say it was a universal fit or generic or some such nominal fit?
Was returning it an option?
I think I have read that Inland Andy had this part (as well as others) specially aftermarket made (and improved). It is good business reasonable that he would not be inclined to have many different models made if there was very little difference in them.
I would hope that he might tell us exactly which year model the original he sent to be duplicated was from.
Also I wish we had a reliable record of the change dates and general specs for the times that Airstream changed the profile of the arc or radius of the fuselage itself.
From pix of ass
orted rear-ends it is obvious there are variations.
BTW I notice a similar revelation at the beach