Think he's right on the first part (metric) wrong on the second (Birch) shell (Beech) ringSooooo, he thinks yes they are metric and thinks they’re maple with re-rings. Hmmmm. Doesn’t seem to sure.
In the Sixties, was there much difference between Beverley and Premier?The International shells started around '68 and and there was a mixture of International and Pre-International drums between '68 through '72. It is always a good idea to check though.
Pre-International shells were NEVER METRIC. Prior go moving to the metric system Britain used British Imperial Units and that is what they used for sizing their drum shells before adopting the International standard for drum sizes.