Delta has a good track record of buying a/c that are not new provided the offer a worthwhile return upon investment. I am sure DL has engines that are common upon some of their aircraft that Continental had. P.S wings of a 400 on a 200 would not make much sense. The 200 wing is a bit oversized as is.It's not like airlines couldn't have ordered a 767-200 with wings and avionics from the -400. They didn't because it would have been a horrible investment. Anyone want to guess which aircraft United is retiring next?