Jean,
I sent an e-mail to the NARA asking for the Camp Report, and another one to the National Archives (UK). They have an Red Cross Report (Ref. no. WO 224/175) concerning Prisoner of War Camps in Europe, particularly also the "Seigburg Lazarett" from 1944: https://www.nationalarchives.gov.uk/catalogue/displaycataloguedetails.asp?CATLN=6&CATID=27524. Today they answered with an estimate, the copying cost for all 116 pages would be 52.20 Pounds. That's quiet much, and I don't know what I would pay for, and all information is from sometime in 1944. I could also send them a description of what I'm looking for, but: What am I exactly looking for?
If your father was was in Siegburg until the bomb raid of 3rd March: That was before the Ludendorff bridge and Bonn were taken. How could he know that he should run in direction to Remagen at that moment?
So many questions
Christoph