Model RF40A and RF45 Advance Remote Sonar Sensor or both compatible with my RF10

My question is, does anyone have one laying around not in use that they could part with? Or know of a place I can get one. My sporting goods store doesn't sell that individual part.
Any help would be greatly appreciated. I'd like to get it back up and running before I'm on the water every week this year. This thing has been a tremendous help in locating structure and helping me dissect a lake bottom from my tube.

fishnislife