The 2 pivot points for the control levers will have to be made up in order to make this work and then you'll have to drill the holes for the front ports. If you're going to replace the 1250 parts with the 149 parts, you'll have to get the reducing bushing from the later model quietline model or make your own.
Less screwing around if you sell one of the 149s and complete the 1250. That way, you avoid the PO mods that we all have to deal with. This will keep the value of the tractors higher at the time of resale.
Just my
.
Happy Cubbing!!
FFGino