There are so many versions of Mortgage Lifter Tomato out there it is almost scary.
Varieties change over the years, some more than others. They really do. In different ways. In the case of Mortgage Lifter, they have become variable depending on the source of the seed. Some bigger, some smaller, some with yellowish shoulders, some that crack, some that don't.
Add to that, supposedly there are about 5 different varieties called Mortgage Lifter Tomato, one or two from Australia, a bicolor version, a yellow version.
Plus, chance cross pollinations happen, and sometimes when it happens with a very similar variety such as Belgian Giant or similar enough like Bonny's Best, it might not get noticed until the seed changes hands a few times and generations. That's what has happened with Mortgage Lifter Tomato I'm sure.
But it can be a good thing! It leads toward DIVERSITY. I'm sure there is true and pure Mortgage Lifter out there still.