In late on this one, but have a good input for filling the 16 oz bottles...

A company in Beaverton MI called K-M products sells a product called
"MacCoupler"..it's distributed in the US by Cabellas(SP?) likely others
too...as cat #2063-1

"Refills small cylinders in 1 minute or less...do not refill in temps
above 85F"

Uses the "chilled cylinder" method...lots of warnings and instructions
on the package, so save the packaging...

I have no affiliation with this company, just a stack of bottles I see
at campgrounds every time I'm out being thrown away that can't be
recycled any other way...so I'm going to try it...YMMV...yada, yada..

Den