It depends on what the supply pressure was when the IP measured 127psi. If it was 3000 (i.e. full tank), then that's pretty low. If it was well under 1000, that's in the range. Since the MK2 is an unbalanced piston, IP will drop 15-20 psi (I can't remember exactly) between the supply pressure of a full and near empty tank. So a good tech will set it on the high end with a full tank. I think mine is around 145 at full, and that way it doesn't drop below 125 when the tank is close to empty.
If the IP on your reg is 127 with a full tank and it was just serviced, that tech didn't do his job very well. It will work, but with an unbalanced 2nd stage it's not going to breathe very well at low tank pressures. Someone, either you or that tech or a different one, needs to add shims under the end of the spring to bring the IP up so that it stays within 125-145 psi throughout the whole supply pressure range.
There is a little problem with doing this after the fact; that HP seat now has a small groove in it from being pressurized, and you have to take it apart to put the shims in. Then when you put it back together, the groove might not align perfectly with the sharp edge of the orifice (that's the part that cut the groove) and you might get a little IP creep. It might be fine. If it was mine, I would try adding shims, and if that fixed the IP and also didn't cause creep, I'd count my blessings and dive with it. If it started creeping but the IP was good, I'd take it apart again and replace the seat, they are not expensive and they last forever.
This is why a good tech will measure the IP before rebuilding, to be able to make a good guess about how many shims to use. Sometimes the reg creeps so badly you can't really tell, but usually you can. It is a little bit of a guessing game.