Gary,
Do you just need to know the OD of a bottle that will fit? I can measure up my bottle for you if that's all you need.

The last time I got involved in this was 2014, at that time Norris Cylinders in AL could supply a cylinder that fit the 27. But they had some old inventory from purchasing Worthington in Canada that were supposed to be the same cylinder but the OD was just a bit larger (QA/Spec/Tooling issue) making it not fit the rear cuff glued to the side of the gear enclosure on the 27. So if you go the Norris route you need to get them to check the cylinder OD just in case the old Worthington inventory is still a problem.

I identified a possible alternative that might work with the addition of a thin plastic sleeve on the bottom to enlarge to OD slightly it was a Luxfer M15A composite cylinder.

I ended up with a steel cylinder that fit from Norris via John Murray at Eastern. Calling John, Then Rex, then Norris would probably turn up a cylinder that fits.

SF