HI Hans
Unfortunately I do not have an electronic build blog but I have made notes and wiring diagrams by hand as far as I went. Retrofitting a Deckel FP series mill is really not that difficult as they say. It was my first experience with Linuxcnc and I managed to do it in about 3 months devoting only some evenings and some weekends to the job.
The machine is now fully operational and reliable. I had to replace the linear encoders with normal TTL encoders used with off the shelf DRO's and although the resolution is not as good as the original Heidenhein encoders the machine is still pretty accurate. In my opinion, if you want to machine to tolerances better than 5micron you need much more than a 1980's Deckel! There are ways to convert the sin/cos signals to 5V TTL but the above solution is much easier and cheaper.
I re-wired the machine from the ground-up. This is partly because I didn't have the original wiring diagrams but if I have to do it again, I would do the same.
The most frustrating part of the project was learning how HAL and its connections work, Ladder programming etc, but all that is documented and I advise reading the integrator's manual carefully.
Regards
Henk