[mkgmap-dev] Map ID: In-file replacing

Good evening, I thought it would be enough to just search for the map ID in a .img file and replace it by a new one. Well, after some research I found out that this is not true. http://svn.parabola.me.uk/mkgmap/trunk/src/uk/me/parabola/imgfmt/app/trergn/... I tried to check out TreCalc listed there, but it would not compile ... Would it be possible to change mkgmap that way that it supports in-file replacing of the map ID (without regenerating all stuff)? Simon