GB-64 1/48 P-51D - One Trick Pony

I think that may be the parachute pack, albeit lower than I would expect. Note what looks like the pocket for the "D" ring ripcord handle (arrowed), although I can't see the handle itself, or the flexible tube housing the ripcord cable, which ran back over the shoulder, which may be hidden by the oxygen mask.
As it seems that the kit part has the cushion moulded onto the seat, I wouldn't worry about it, and just leave "as is", as it is possible a seat cushion was fitted in this instance, and maybe a change to a seat-type parachute pack, as used with the P-47.

There's a build thread over at Britmodeller with excellent reference pics and discussions.


Somewhere in there is a lengthy discussion about the back cushion. IiRC the conclusion was that there often was a cushion - not a parachute, not a flotation device, but a simple padded cushion.

Thanks Andy. I got the above photo from there. That guy is way outta my league but I can get some good ideas from there

Many thanks Andy, it's a gem of a site.