Small price if I like the way it rides, proportionally it looks like an inch could come off with no real harm done to the frame. Look at Giani's, his tube is shorter, yes a smaller frame but still less sticking out. I’ll certainly be finishing it before making any decisions.
I've also seen quite a few with shorter tube and judging by the colour scheme on yours, if 2cm is taken of no one will ever know, unless sold on here :)
But if it is done I would be careful with that hacksaw, certainly not a hand tool jobby, would get it cut by a pro, nice and clean
Meaning it's slightly too big for you?
I'd try no to cut such a beauty :-(
They also lose value a lot.