The B-17 ferried out of Paris, Texas, was 44-83525 and is now stored by Kermit Weeks. Weeks purchased it from Burchinal.
As for the Burchinal B-25 in question, it may have been TB-25N s/n 44-29127 (N9899C). Burchinal obtained it in 1976 and there was some big disputes over the airplane. No indication in the FAA registration record that it was involved in a belly landing. This airplane is now reported stored in Anoka, Minnesota. Registration records indicate Burchinal at one time or another had seven B-25s registered in his name: N3680G, N3698G, N543VT, N9115Z, N9446C, N96GC, and N9899C.
Also, no NTSB reports seem to match with any B-25 in a belly landing in Texas in the 1970s.