[Radioroslyn]

What I can tell you from experience is that most of the time the local oscillator runs above the incoming signal not below. I would algin it accordingly. 
Use the counter to set the 12.455mc (osc) for the dial (12mc) reading. Keep the generator turned way down so there is much avc action and peak the ant trimmer. On the band 2 there is just the high end of the band osc set no ant trimmer. Same for the bcb but there is a low and high set for the osc so you can get the tracking on target, well close. There is no low end set for the sw band so wherever they fall is it. Unless you want to bend the plates on the tuning cap but that effects all bands

I have a 41-300 which uses a similar front end/IF. Works fine w/the built-in loops but try to hook up an external antenna oh my! It's got all kinds of images. I don't one of the 3 pin external antenna adapters that may help. Somewhere there is a diagram of it with the part values.

GL