Brake Upgrade Problem

Having a little issue with my upgrade. In order to speed up the rebuild I farmed out a few parts, one being the rear end. The guy who did it is a jeep guy and very good.....but. He said the backing plates were too rusted, and bent to put back on and asked me to source some new ones. A member here sold me a nice pair of 10" to replace the 9" drums that I had taken off.
Problem.
When I got the rear end back from the shop, I cant fit the Brake cylinder through the hole? It must have fit with the 9" brakes so I'm not sure what has changed. Can I just use a die grinder and make if fit or is something off here? Looks like I'd have to remove at least 1/4 of material.

 

Well.... Obviously the brakes have changed. Does the 10" brake use the same wheel cylinder as the 9"? If not, that's likely the problem. If so, is the axle retainer oriented correctly? The photo looks like potentially the axle retaining plate might be covering part of the hole for the wheel cylinder?

 

I purchased new cylinders for the 10" plates, but the steel from the axle housing is in the way. I remember the member who sold them to me mentioning they came off a dana 27, but I put them on a 44. Would that make a difference?

 

Better Photo