Thanks, Pete, but as I said, PTLens (which I own and have been happily using for the 14-54mm) does not completely correct the distortion for the 12-60mm, it leaves some residual barrelling, which must be corrected with the PS lens filter. I am going to ask Tom Neimann to tweak the profile for the lens, but am also looking for other alternatives to try as a fallback.
Somehow missed the 2nd paragraph - phone rang or the 70 year old brain misfired again! In past communications on the Oly DSLR forum, Tom Niemann mentioned that his profile is correct only for infinity focus - then +/- 1 px, which sounds a bit far-fetched, I must say. I didn't realize that DXO supported Oly's lenses, and glad to hear that fully corrects the 12-60's 12mm distortions. I'm off to download thr trial version of 6.x. Maybe a PS plugin is in the future?