rear brake shoe size

[mbev51]

hi been told by my local (french) ford dealer when I give him the reg and vin numer that my transit fwd 2002 swb has two sizes of rear shoes listed. I've just looked at the drums and there is 256 written on them together with other info. Is this the size (the smaller set of the two listed)?

[mbev51]

just to add to my post, I was told there was two sizes 254 and 279. How do I work out which one I need?