I've got a LaPeppina that I PID'd also. Actually, they're all the rage, I hear...
Also put a brew pressure gauge on it. There are two thermocouples (T type). It's placed right at the turn to go down to the dispersion screen. There's also a brew pressure gauge. I'm most happy about the fact that the two in front are removable and the machine can be returned to stock (basically). Normally, there is a flat head screw there, just like the hex screw on the front of the E61 (same purpose too). The head sits in a counter bore, which happened to be just the right* diameter to thread 1/8 NPT... So if I remove the pipe tee and put the screw back, you can't tell the c'bore is threaded.
*Actually it's a little bit too big. I had to use a modified (ground down) pipe tap to use the larger part of the taper, and I had to cut about 3 threads or so off the male threads on the pipe tee.
The other TC is for the PID. The pocket/cup that it's put in is right above the inlet to the cylinder...
The PID box is the common Fuji 1/32 DIN.
It was a fun project, and it certainly makes the coffee more consistent.
Oh, and the brew pressure starts at 6 bar and drops to 3 by the end of the 2 oz shot.