I think your filler/level plug is on the right. You need to get under the transmission tunnel cover (leather?). You should find an access plate (or rubber bung) in the side of the tunnel - the level plug should be under that.
More detail should be on GoMog or Morganatica.
B3808 RTA 51R '76 4/4 Ivory 2 seater
'01 Freelander TD4; '90 Defender 90 SW