For XK120, all models. 18 gauge pressed steel with welded reinforcements and rear special lip included and welded.
Early style: BD4172 (X34) is 9" tall at the front (adjacent to fuel tank)
Later style: BD7778 (X34C) is 10" tall at the front
All DHC and later FHC (changeover sometime in 1953) take the later style. Some OTS cars may also take the later style. Please measure the height of this part on your car before ordering.