Thanks Robert
This is really useful stuff 
- does the book give details of the other pilot's claims made that night?
It sounds like I need to find a copy of the book.
Does anyone have any note on Becker's 2nd claim: 21:53 around Paderborn ?
I don't have my notes in front of me but I think the closest match for his 2nd claim is:
DV384 at Obermelbecke (70km SE of Dortmund) - I estimated crash time at 21:45
So I am happier with claims 1,2 and 3.
But I am still concerned that an experienced pilot like Becker reports claims 4, 5 and 6 as NW Frankfurt - when they all South of West.
Why might this be?
It is helpful to note that claim 5 22:38 LW417 should be close to claim 6 22:39 LW512 Mohrweiler. To attribute LW417 as claim 5 suggests that someone has identified it on the ground. So I wonder why Chorley or Lost Bombers doesn't have a record?
A few more questions if I may:
Did Allied aircrews sometimes confuse JU88's & Bf110's ?
What was a typical operational speed and range for a Bf110?
Wiki tell's me: Bf 110's maximum speed increased to a respectable 541 km/h (336 mph) with a range of approximately 1,094 km (680 mi)
(A quick car trip round the crash site gives 991km)
What systems would Becker's Bf110 been equipped with?
A quick summary of how it's shaping up:
Becker takes off 20:20 and heads North until he intercepts the bomber stream near Padderborn. He enters the stream and in the next 30 mins claims 3 victims. By now the raid on Frankfurt is well underway and Becker can probably tell this. So he goes looking for the returning bomber stream heading South he intercepts it between Mainz & Trier and in 10 mins claims 3 more victims. At this point either due to low ammo and/or fuel he returns to Finthen base at 23:13.
What do you think?
Cheers Robert