Hi there,
The seats for the FGA.9/Mk.58 Hunters are Martin Baker Mk.3h seats and the one in the 1/32 True Details set is an Mk.2h ideal for a Mk.6 Hunter. That one differs externally from the 3h in the knee guards so is a matter of modifying them to get the shape right. The other option that im aware of is to get a hold of the Aeroclub or CAM Mk.3h resin seats in 1/32 but i havent been lucky with those yet..... or you can do as i did by getting rid of the kit cushions and adding like 40 parts to the kit seat to make it at least similar to an Mk.3h.
Cheers
German