If the INS can drive that AP (which I think it can), I will offer some popup gauge implementation for this bird soon.
Should be the same as on my 727 and 707 modifications, so nothing new.

I just need some time to check the plane myself, so "a few days" might be the most precise answer here. Maybe Mark or some other guy comes up with a implementation in the meantime.
As far as I can see, the normal technique can be used here, no rocket science needed.  :)

I also suggest a 2D Autopilot popup as seen on the 707 for easier operation, especially when aiming for a fixed climb rate.