After extensive testing, I have decided this model is no good as the top connecting parts are too weak. In my initial search for an existing model I failed to find one. I have however now found one that I highly recommend.

https://www.printables.com/model/362719-spool-arm-for-prusa-originalenclosure-spool-holder

I will leave this model up if only to guide people to the above link.

I needed additional Spindle arms but could not find one, I guess as the original is injection molded an .stl doesn't exist?

I printed mine in PC and at 100% to give me as much strength as possible. 0.3 layer height. No supports were added. I wont upload G-code file as you might not agree with the way I printed mine.