Ditto on that, the suspension and running gear is the most challenging part of any RC tank. It is often the deciding factor that determines which tank the modeler chooses to build. This doesn't mean building an M24 is not feasible in 1/12 scale, if you have access to a lathe or CNC mill, the road wheels can be easily made. 1/12 scale is somewhat close to 1/16 so you might be able to find suspension arms or springs that will fit the tank. As for the tracks, I have seen guys who have used welded hinges from the hardware store in combination with bicycle chains and sprockets, the catch is that these types of tracks do not resemble the real thing. So it also depends on what level of accuracy you wish to achieve.

On the other hand you could build in 1/16 scale instead, like you said it is simply a re-scaling of the CAD drawings in Solidworks. You might be able to fit the HL M41 Walker Bulldog road wheels and tracks onto a M24 chassis, but I see that you've already started the frame, so that might be a bit tricky. You can also consider using the HL M41 tracks for your 1/12 build too, these tracks are way too wide for 1/16 (the HL M41 model wasn't entirely accurate to begin with) so they might look to scale in 1/12. This still saves you a lot of effort since now you only have to worry about the road wheels and drive sprockets.