HGW do a seatbelt set for the Fee. Its like all their other seatbelt sets, very nice.
HGW also do a set of wood grain decals for the Fee. Haven't used them yet, but first look is that they are intended for the version with the fuel tank under the pilot's seat. There *might* be enough wood grain decals to do the pilot's locker version (which is what I will be building). Utility of this set would depend on your ability to paint wood grain yourself (not that hard using artists oils). That set also includes a small quantity of CDL textured decals for inside the observers cockpit.
If you wanted to detail the bombs HGW also do a generic RFC armaments set. Looks nice especially the bomb racks, and includes the arming vanes on the 20lb bombs and thin fins for each of the bigger bombs.