I believe you are correct.
https://www.youtube.com/watch?v=0bgiqKbnuyM
There are several videos on youtube of survivors returning to search the site of the old camp.
Also this. Another composite character for Virgil Hilts.
https://www.youtube.com/watch?v=lvJD3HUDYj4
https://www.youtube.com/watch?v=d2Hf1rKkgus
https://www.youtube.com/watch?v=2-H4fJsP5eg
Another short history of the escape and the movie.
https://www.youtube.com/watch?v=Bg8frReTze8
https://www.youtube.com/watch?v=BuYx-z6r3tQ
https://www.youtube.com/watch?v=Li8GeT5Rjww