Scaling UV shells when stitching I have 2 UV Shells. (UV Shell A) and (UV Shell B)... (UV Shell B) is 200% the scale of (UV Shell A).

If I stitch them together they both retain their original size, but the edge where they are stitched is scaled to a size midway between the 2. 

I there a way that when I select an edge on (UV Shell A) and try to stitch it to (UV Shell B) , but have (UV Shell B) scale to the size of (UV Shell A) so that there is no distortion in the UV Map?   I know other 3d apps have this option or do it by default... is there a way to achiever this in Blender without having to manually go in and scale the UV shells?   

Note:..  (UV Shell A) has to remain where it is as it's already in the correct place, so I can't just map them again.
You can do it using Live Unwrap and pinning vertices of the islands.

First select one UV island and hit V button to pin all the vertices, then select and pin one vertex in the center of the second island.



Then remove UV seam in the place where the islands should connect.

Change the mode to Live Unwrap.



And grab the center pinned vertex of the island and move it until you have a desired result.