You're very welcome Guy!

That's a very reasonable philosophy, and I don't think you've got it wrong at all. I go for accuracy as much as possible, but with WW1 aeroplanes I have learned, as I think we all probably have that this is not always possible. There were so many exceptions to the rule that you just don't always know what is correct and what is not. Poor restorations, age and weathering and conflicting contemporary accounts also make the determination of original details such as colour close to impossible in many cases.
I don't know for sure, but I think that the bulkhead behind the seat is original in D.5390 / '17. It was almost completely original before it was restored by a well meaning group in the late 1960's and early 1970's. On the subject of the mixture of lozenge and plain fabric, this one had a mixture of both! In the quite well known photo of it at the factory I think I can see the purple and green patch camouflage on the upper surfaces of the upper and lower wings, the light blue on the underside of the lower wing and the lozenge fabric on the underside of the upper wing, as it was when it was captured. I often wondered if it had been re - covered during service but I have several copies of the factory photo and the better copies seem to indicate that it left the factory in this very unusual mixture of old style and new style camouflage.
Thank you very much for the reference to the Windsock Datafile Special Lance. I know I have seen photos of the screen but I don't know if I have photos of it in my collection, if I have seen photos of it published or if I simply remember the colour from one of the many research visits. I have even worked at the AWM on two occasions, but research requests are not always easy to have approved, even for staff members! Generally it's not a problem if the necessary approval is sought. I will have a look through my photos, but it could take some time so please don't be shy about a reminder here or there if you don't hear from me. I intend to catalogue all of my photos, but it is going to be an absolutely massive job, given that I have an estimated 10,000 or so, and who knows how many tens of thousands of digital photos!

Buying photos on eBay doesn't help either. I bought some very nice 74 Squadron photos a few nights ago (a famous but oddly difficult Squadron to obtain photos of), and some RAF photos taken in Egypt tonight. I probably buy between about 20 and 50 per week! More to catalogue and put into books (eventually!

- it's a very time consuming exercise!) and like all of us I'm not getting any younger!
I don't recall seeing a lozenge cover behind the seat of an Albatros D type either. I know that at least one Fokker had a lozenge cover behind the seat, and it's still there! (the Knowlton D.VII of course) The earlier Fokkers which had plain fabric covering almost certainly would not have had lozenge covers, since the reason they were not covered in lozenge was that it was not used at that stage. Albatroses could be a different story though, since the covering seemed to alternate between plain and lozenge fabric, and in the case of D.5390 / '17, which almost certainly means that this also applies to other Albatros aeroplanes a mixture can be found on a particular aeroplane. Dan San Abbott stated that they alternated every 50 or so aeroplanes (I think I remember reading this in the last few days) and just to give an idea of how unpredictable the covering is D.7161 / '17 is now believed to have been covered in plain fabric which was painted in patch camouflage, even though it was restored in lozenge fabric, which would naturally be expected with such a late production aeroplane. If Albatros used lozenge fabric bulkheads behind the seat it would be anyone's guess as to which ones had lozenge fabric and which ones were plain fabric. The external covering could be an indication but there is no guarantee that the two match, unless the aeroplane was constructed before the introduction of lozenge fabric. I recently read an estimated date for this but I can't recall where I saw it.
Regards,
David.