The figures are from the scale technical engineering drawings of the aircraft, and are correct. I would provide a scan, but don't have a scanner!
inches offered is meaningless, it fails to take account of Delta offering a 6 abreast First Class cabin against First Choice Airways' 7 abreast throughout the aircraft.
How about the number of inches offered nose to tail?
4 First Class rows @ 40" = 140"
34 Econonmy rows (not all full rows) @ average 31.5" = 1071"
Total = 1211" inches nose-to-tail
First Choice Airways
9 Premium rows @ 36" = 324"
29 Standard rows (not all full rows) @ 33" = 957"
Total = 1281" inches nose-to-tail
So in those terms FCA
are offering the approx equivelant of 2 extra rows of seats.
Now, when you factor in that Delta have a mid-cabin galleys which First Choice don't have, Delta have an additional mid-cabin toilet and numerous closets and stowages that First Choice don't have, seems reasonable that removing the above items would provide that space doesn't it?
Charter airlines will aways make far more efficient use of space onboard their aircraft than scheduled carriers can...