Whig,
Appreciate your concern and for most situations it's probably the best advice but I have to report it is now working after very slight stoning of the right side of the extractor as suggested by BR.

There was a somewhat complex story behind the story with this rebarrel job and if with an easy fix or oversight on my part being pointed out I could avoid the hassle and risk of shipping this back and forth it would be worth the effort to explore it and this time it worked out.

Thanks everyone for your comments on this post. KCA is a great resource!