It is not too difficult to get the cuts clean.The razor-saw makes the edges quite smooth.Then I use a glue which is quite thick.But this time I use MrHobby Lemon glue which is like a water and can go along splits.
More excellent micro-surgery from Dipl Eng Doktor 'Wurgermeister' Wojtek!
Wojtek, I now have one of those razor saws! Matt very generously and kindly sent me one from the U.S., with blades and spacing bars, in order to make multiple parrallel cuts if required. I've used it twice so far, on small jobs, and it's fantastic! Don't know how I managed before - thanks again Matt!!