SO23 help with dimensions of cushion wood-back

[Atlantic]

Can anyone verify these seat dimensions please? I took them from what I think is an original set, but I want to make sure that there was no hacking of the original and/or that these seats really belonged to an SO23 before I cut and upholster new wood:

This surprised me: The seats were differently sized (depth):

45" width x 23 3/4" depth
45" width x 25 1/2" depth

Is this correct ?

Backrests were same size:
45" x 10 3/8"

Thank you again!
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"If we believe absurdities, we shall commit atrocities." [Voltaire]