Aligning two map images as layers

[FingerPicker]

Hello,

 

I have two map tiff images of the same map grid.  Each has a collar or border that matches and would allow for alignment but the scans are of different size. One image has three sections obscured and I would like to replace those obscured areas with the portion of the other map that matches.

 

I have tried importing both tiffs as separate layers but am having difficulty finding the right tools to align the two layers. Are there tools/steps that would allow me to align the two maps together without skewing the image that I'm adjusting?  The scanned tiff files are too large to upload here.

 

Thanks,

 

Peter

[BoltBait]

Change the opacity of the top layer to 50%, do your alignment, then change it back to 100%?