Stig,
I've looked at A6844 & B6844 and they are a MF.11 and Spad S.XIII respectively. As indicated I'm never really that trusting of my eyesight,but still read 8844. Having looked at the various options so far, I think I'd be correct when I say that in any event according to
http://www.airhistory.org.uk/rfc/Nieuport.html has a serial where the first two digits is 68 higher than B6837 so a reconstructed aircraft looks probable, unless serial wrongly applied. So I do wonder about airhistory.orgs id of B.E.2c B8844, but I guess a photo would be required.
Regards,
Clint