lost title & licensing questions???

Anyone know how I can check to see if another mustang i'm buying is ligit? here's the story. i'm looking to buy another mustang. there's this guy down my road... well i bought a mustang from his son earilier this month and everything went well with the title/registration. so his dad tells me the story behind the mustang i'm looking to buy from him/dad. the dad bought it from a soldier who was heading to iraq. he says he might be able to find the bill of reciept somewhere, but it might be lost too. well this
soldier never got the title transferred or found it, something along those lines.
well the guy went to iraq and never came back... the dad heard this guy died over in the war. the tabs expired back in 2003 so it's been over 3yrs and no contact from this soldier or title paperwork. well i'm trying to get a title for this mustang. i know i can file for a lost title, have a bill of reciept, etc. but i'm not sure if the TOPIC OF: him not finding the original bill of reciept and not ever having recieved the title will cause a problem with the licensing department???? if he writes a bill of reciept to me and release of interest... am i able to get a title/file for lost title even though he never actually recieved the title???

i guess i should also mention there is NO MOTOR OR TRANNY to run serial number.