Hey!!! Or should I say...Hay!!! I have one of those!!! It was marketed by Deere in the early '60's, and it's called a hay fluffer. It works well, but the only trouble is that the hay gets caught up in the tines, and you have to clean it out often as you're fluffing. People got frustrated with them, so they only marketed them for a few years. I use mine if I cut SMALL areas, and I want the hay to dry out faster for baling. It really does fluff it, and it really does decrease drying time...but you have to get off the tractor and clean out the tinnes about every 15 minutes..if you're lucky...so it isn't really viable for large acreage haying.
I picked mine up real cheap at a farm sale. Like you I never saw one before, and had to see if it worked. I did a lot of research on it to get the little info I have on it.