I don't think there were many produced so what you have is fairly rare. It might even be unique.
In case you don't know: After Speedex failed a new company (Armstrong Tractor) purchased the assets and moved them to Armstrong County, PA. They re-branded the tractors Strongland and targeted the export market. Aside from the normal challenges of that market they made some design errors and quickly were driven back out of business by lawsuits.
The Strongland tractors were based on the large frame Speedex tractors of which the Speedex 1631 was one.
I also have a Speedex 1631, a 1994 with hydraulic 3 point hitch. I love the tractor and would really get use if I had a loader.
Post lots of pictures please!