I've just bought an octave mandola from David Kilparick; one of his Romanian instruments. I think it's pretty good for the money. however, the intonation was very poor largely because of the very light guage factory strings. I have put on a set of mediums (14 first strings) and it has done wonders to the tone and intonation; I had to file the bridge and nut grooves for the last two strings though to accommodate them better. The problem now is that it is much harder to play! David has suggested filing down the zero fret. As I haven't done this before has anybody got any tips? Also, would the bridge need shaving down a bit as well? Thanks.