I had a little pamphlet catalog from Harold years ago, and I still have it somewhere. I don't know if he made them, commissioned them to be made, or just resold them but, as I recall, he used to sell cages for FL250 and 350's so that may be what you are remembering. He also had fiberglass bodies for the 250, the HRD (powerblock?) clutches, and some other stuff.
My first dealing with him was buying a set of FL350 nerf bars from him and had him ship to me on the east coast. I remember him sending me, free and unsolicited, some kind of little tube and some hand written instructions on how to eliminate the FL350 starter
motor ((
Internal Combustion Engine ? )) from filling with oil. I used to get calls out of the blue from people that wanted to ride on the east coast, referred by Harold, and many of those panned out to be great ride experiences. He really was a great guy and so good for the sport too. Over the years I really enjoyed reaching out to him on several occasions and talking about the sport of these buggies. He was always willing to take time to help me out. He connected me with 3 of the many buggies I have owned through his many, many contacts.
I had spoke to him just prior to flying out and had planned to meet him during my first CA trip a couple years ago. When I got out there, I called for a good time to stop by and was told by his family that he had just passed away. Very sad day.