Looking at the TCDS, there is no 310F, as such, although it appears that you have a 300 series aircraft.
Using the generic MAC data in the TCDS notes, the data fits your envelope reasonably well but not quite as closely as I would have expected given that the envelope appears to have been drawn reasonably well.
Could you please advise the following from your OEM manuals, in metres ..
(a) LE MAC
(b) length MAC
and confirm that the presumed trim datum is 26.67 metres precisely ?