RE: (I believe you want a type 41 to replace it, but I think a type 42 is
the same size, just a larger
capacity)

Actually the Group 42 is smaller both in dimensions and capacity.  The specs
on a Group 91 says they are the same dimensions as a 41 but slightly higher
capacity.  At least one very knowledgeable list member uses the Group 91.
As for me, I've never been able to even see one on the shelf at the store so
I wouldn't know where to get one.