Cutler-Hammer makes 'Renovation Loadcenters' and will likely make custom guts for you.
They pitch this service in their catalogs.
You might contact them.
You did not mention the specific body cavity dimensions. They are more important than the old mounting holes.
SQD nearby fits...
NEMA1
38x14.25x3.75= QO42L225
33.75X14.25X3.75= HOM30-40L200TC
NEMA3R
34X14.25X4.5= HOM30L200RB
38X14.25X4.5= HOM40L200RB
