Hi Chris
I think that I agree with you. The ship's radio aerial was destroyed in the first pass so it would not be able to transmit an SOS and consequently the aircrew would have to try to read the name. The Empire Bison had not had that name for much more than two months and it may not have been known to the intelligence officer debriefing the crew. However just to be sure I do need to try to check on the movements of the Empire Scout.
I have struggled to understand the Luftwaffe Gradnetzmeldevefahren as explained on
http://www.stormbirds.com/eagles/
and I think that location 25W/5520 is roughly 54 N, 15 W, which is close enough to the ship position estimate of 55 N, 18 W (at 0600 the ship would be at least 18 hours beyond its most recent positional fix). Was 0008 hrs the time by GMT or an hour ahead of GMT? If the ship was adjusting its time to keep in step with latitude then I guess the plane was 6-8 hours into its flight when the attack started.
Please do you have any further information about the flight?
Thank you very much for your help.
All the best
Gobbo