As Socrates allready mentioned
I made a masterpiece (wich I still have) and then casted a form
I can only suggest , take your time for cutting , be patient , better cut five times a little bit then one time too much
The corners in Gassy's medieval town were mine ,traded some stuff with him
Those roofcorners were resincasts and immediately coloured
Sadly the form got broken quickly and I didn't have time , money , and lust to make another mould yet