Copying edge length...

… from one mesh to another. Good evening, chaps. Here’s a picture as visual aid for my rantings :spin:

These two meshes are very alike (B is smaller than A, but can have the same dimensions without mush fuss), however the edges (seam lines actually) at the arms and legs (circled) are also larger on A than they are on B (a rough guess would be 20-30%).
Now, my question is if I can copy the measurements or even replace the seamed edges on mesh B with those from mesh A. using either a script or a tool?