No relationship to the earlier piece shown on Bonhams, which is my favourite style of decoration of Monart.
It is unfinished because it is not polished. Amber bowl on eBay is probably not Monart.
Wheel shown could cope with a lot of different sizes from quite small, what you see on the grinding is not the shape of the wheel but the path that the grinder followed. You can use it in quite the same way as a bench grinder for metals although to see a skilled grinder at work you would be forgiven for not recognising how delicately they actually handle the pieces.
I should not worry too much about finding the colour code for yours. The table on ysartglass.com was first created in the 1980s and expanded online from 1999 to around 2004. Gary has done a lot more detective work on colour codes too, but with 500+ and many a/b/c variations are countless and will probably never be known, plus of course after WW2 it was necessary to get some colours in UK until Kugler were producing again. Adam A could quite likely tell you if your is a Kugler colour or not... which information would also serve no dating purpose but just be interesting. Aventurine of course came from France and if from a wholesaler there, was probably Italian anyway.