Has anyone done a restoration job on bruised or damaged Mk IV canisters, and are the AC service decals available?
Is there any cross-sectional drawing showing the internal construction?
My initial thought was to cut around the base about a cm inside the rim and remove the domed base along with whatever is attached by the central rivet. Then carefully make a replacement dome to fit neatly to meet the rim, overlapping the flange remaining, and use it to rebuild the internals. I have one where the central tube has separated from its bottom connection and rattles around, and another with something rolling around inside. Both also have the captive studs not captive anymore and are turning.
These faults don’t really make any difference to their operation and the studs can be carefully brazed in place, but the dents are very unsightly.