Is it bad writing?
Bad handwriting in the 16th, 17th and 18th centuries is as annoying to the reader as bad handwriting today. There is little that the palaeographer can do with a case of very sloppy handwriting except deplore it.
If this hasn't solved the problem try another option:
Capital letters
Interference
Superscript marks
Double letters
Ligatured letters
Idiosyncratic letters
Return to the problem letters page.