Florence,
We had a similar situation with our oldest son in that we used Handwriting Without Tears with him for cursive for several years, producing a big scrawling handwriting that he couldn't seem to remember how to do correctly.

Then, we did 2 years of Bob Jones handwriting, which confused him more. We've found that Cheerful Cursive does a good job of teaching correct formation and teaching kiddos how to read cursive. It has them read a sentence or words in cursive and then print the word in manuscript below. This is an excellent teaching tool. The workbook also shows all the different ways a cursive letter can be formed. Last, it is a pretty type of cursive in a smaller, but not too small" font size. We've had good luck with it.

Until your son gets all the way through Cheerful Cursive, I wouldn't require any cursive handwriting from him. So, he'll be on a cursive break for a year while he works through the workbook.
At the end of Cheerful Cursive, the following year make sure to have your son do the copywork assigned each day in our guides in cursive (as mentioned in the plans). This will help cement the skill.
Blessings,
Carrie