Can't tell much by the picture, but might work, might have to put some weight on it to get the tines to dig in. Do you have that many places that you can't get your JRCO to go. Could just use a hand rake or a power dethatcher. There is no many places I can't get my JRCO to go. Marc
I have a similar dethatcher on my 21" John Deere. It works relatively well, not as well as a power dethatcher, but not bad. The good thing is you can collect debris at the same time. That unit you looked at should fit your toro prolines.
For very small areas, you might consider getting a Mantis tiller with their dethatcher attachment. That thing works awesome but it is a lot of work pulling it backwards.