Tried those first but no, they didn't work great with the data I was able to extract; those datasets are only handwritten digits which apparently weren't close enough to the computer printed ones.

I think the artifacts from the square borders (eg if it's slightly mis-cropped or misaligned) were also tripping up the model before I had my custom dataset loaded in there.

Edit: I should say this was my first stab at doing machine learning so I may be missing something; definitely open to ideas or suggestions!

Shouldn't you be able to generate a lot of synthetic "printed-looking" digits very easily? Just get say 20 common fonts and render each digit with random rotations and scaling etc.

That's definitely on my list of things to try! Thanks for the push in that direction