Colin at Sellick Equipment was very kind in trying to answer my question. Below is his response.

Terry,

I ran this by some of the "senior" staff here and not one person can remember any OEM using this chassis to manufacture a forklift. If this was a production unit from somebody I'm not familiar with it at all. You could maybe check with a company called Swinger who manufactures similar type machines still today. Sorry we couldn't be of assistance.

Good luck,
Colin Sellick