Aside of being careful to keep everything lined up, parallel & square the build of the Z Axis, mounting the Y Axis and putting all the extruder and hotend parts on was pretty simple and in line with the official Prusa Manual.
Really the only thing I had to find a solution for was mounting my lead screw nuts. Toms version uses 5mm threaded rod and he provides STLs for parts to hold a M5 nut for that. The original MK2 looks like they use their own lead screw nuts. The ones that came with my lead screws had their mounting holes too close together and there was no way to centralise the nut in the Z carriers. I customised Toms Z nut holdahs to do the job – which it seems to do fine.
I will say this though, after building it all I examined the extruder to “sanity check” it and it turns out that it was very tricky to feed filament through the extruder and into the telfon tube running to the hotend. I will do an extra post discussing that as I think it is a mis-match between the extruder body design and the commonly available MK8 hobbed gear. I think if this was left unchanged, apart from having to use tools to get it to feed in, it would put a lot of load on the extruder stepper just to overcome this tightness.
I would also recommend that if you can squeeze an extra £20/$30 to get a Z axis frame laser cut – do that. It will save you a lot of time and insecurities about the Z axis being parallel and square. My wood will probably work fine, but it’s just a lot harder to make sure it is correct.