Ah...ok. Have now halted the operation. Before doing this I gave my skin folder a severe pruning to get rid of all the old, often 2k skins that I'm never going to use and didn't want to inflict on other peoples drives.
I see my skin folder is now at 19gig and growing and is now filling with skins that others have d/l'd over the years and don't use either.
Thanks for your efforts FT but I don't think this is for me.