We have several that we have had for years and years. The company went out of business in the late 70's/early 80's I believe. The carts were some of the first that we ever owned. One was used by Tamerlane's Golden Rose who was the Shetland Congress Champion Over Roadster Pony in 1965 and 1966 and the other's used by Crescent's Copper Misty who was one of the first Shetland's to earn their Hall of Fame in 1969. Both ponies were owned by my sister and I until their deaths well into their 30's. Rose was born in 1960 and Misty in 1962.
My friend has a Wilform cart and loves it. I had the chance to buy a Wilform Pony cart a few months ago, but didn't need one that big. I had been looking and looking for a Wilform mini cart and finally settled for the Jerald because I couldn't find a Wilform.
Our jog carts and racing bikes on the race track were Wilform. They were very durable and we never had a problem with them. Of course these were for big horses (in the 70's). I don't know about there quality in a miniature horse cart.