Several options can be considered. "Thin" Fat Dots between the wood and metal frame with a "Thin" Fat Dot under each of the legs. Or just a Big Fat Dot under each of the legs, or a Giant Fat Glider under each leg wouldn't be overkill in any way. The dBNeutralizer material that Fat Dots are made of have just a slight little "give" to them to accommodate some unevenness and, if necessary, one or more can be shimmed with Post-It Pad Paper, thin cardboard or hardwood, felt pad or etc.
Herbie's Audio Lab