Well by the engine number it is a Model 2 not a 1.Although it does look to have a model 1 throttle control on it.Also I think I see a cigar fuel tap on there as well.Year would be 1956-57.As far as an easy way to un-seize an engine....sorry you'll just have to pull it apart to see what has seized up.No easy way to free it up.really best just to find out why.
