Most expensive aircraft to rebuild?

there's no doubt rebuilding destroyed aircraft ground incredibly expensive. in fact, more of build re-build. there isn't way easilydetermine how such project cost.
however, far know, ambitious project know of right restoration of "doc", b-29 superfortress. it's last of kind , requiring such detailed work boeing assisting @ plant in wichita, kansas. can't find exact numbers, cost of such huge, specialized project must astronomical.

i think hindenburg maybe

Cars & Transportation Aircraft Next