Go to
www.casece.com there is a parts breakdown for the SC150. This can be a great help with assembly sometimes.
Most of the parts are retired by Case. About the only thing I know about some of the later "CASE" poclain series is that with the electrical system they usually switched(broke) the ground wire not the live wire in the circuits. So when you have trouble with a function you are dealing with the ground wire at the switch not the live. Not sure if this machine will be the same, and it won't be hard for you to figure that out anyways.
Most cylinder packings can be obtained locally from a good hydraulic repair shop. You can try
www.epm.com or similar sites. Poclain was notorious for having several variations of cylinders on any one model.
Engine should be a Deutz, you might find a Deutz engine manual somewhere easier than a whole machine manual.
These machine would be a very very rare machine in Canada not sure about US. Manuals would be like finding hens teeth at best. If you have a particular problem with it post a question here. There are a lot of good guys here with a wealth of knowledge.