I second what Mr Stretch had to say. The Rouse hand milling machine is hardly that. It is a milling spindle mounted on a vertical slide of limited travel. No table, no provision for an overarm, unknown spindle taper (if any). In short, it is not going to be useable in a home/hobby machine shop without a LOT of adding-on, and then will be an approximation of a milling machine, and of limited use.
Barker or Nichols hand milling machines (of which many were built for WWII and into the 60's) are usable as they are built. These two are production type horizontal milling machines, but can find use in a home/hobby type shop. These are still production type machine tools, but have enough features on them to allow them to be used for "one-off" jobs.
The type of milling machine needed (ideally) for "one off" type work is a "knee mill" with feed screws and micrometer collars for the X, Y, & Z axis. A variety of small/light duty knee type milling machines were built, and these include: Benchmaster (the lightest duty, low end of the scale), Burke (middle of the scale), and Hardinge (high end of the scale). Bear in mind these are horizontal milling machines, and while capable in that regard, do not offer the advantages of a vertical mill. These smaller knee type horizontal mills were often fitted with vertical milling heads, making a nice package with a good deal more capability. A good smaller knee type milling machine for home/hobby type shops with limited space is the Clausing or the Rockwell vertical milling machine. Small footprint, R-8 spindle taper, and can be moved in a crossover SUV or even a car if need be (taking the mill apart for the moving in a car or crossover SUV).
By the time the Rouse mill was modified and equipped to do any kind of real work, the OP would be in it for the cost of a good used small knee-type mill such as Burke. My advice is to run the other way from the Rouse milling machine and look for a real knee type mill.