http://www.mcmaster.com/catalog/130/3479/94414A713
You'll notice the link above is for the 8mm screw, and the item listed right below it is for the 10mm version you reference. These are both Torx Plus screws.
I know Duracell was mentioned a couple of times in this thread as to preferred CR1620 battery. But just as an FYI for those who care about such things:
Brand - Country of manufacture
Duracell - Indonesia
Energizer - Indonesia
Panasonic - Indonesia
Maxell - Japan by Hitachi
Toshiba - Japan?
Renata - Switzerland
Murata - Japan
Have been quite happy with Duracell 1620s and have a bunch of them.
Would be open to trying Renata in future but no urgent rush to swap.