I can't help you with the SDK -- way too complicated for a simple mind like mine 😀
While you are waiting for someone who actually knows how to use the SDK to come along, you could always simply alias some of the default panels to your imported aircraft. Example: for the MD-11s or The DC-10s I use the default 737 0r 777 panels. Obviously for small GA aircraft you would be looking at the default Beech Baron -King Air etc.
The beauty about this is that you don't have to mess with gauges. If the panel you've aliased doesn't work to your satisfaction, change the 'alias' to another 'alias'.
Yes, i'm doing exactly this, but unfortunetly (for me😀) , i most enjoy flying on virtual cocpit. For example Posky A330. It is allready done with in version for FSX, with defalut panel on A321. so i downloaded VC model and gauges. After that i was playing for log time with panel.cfg and finaly i replaced all of these gauges with FSX defalut. But i can change only type of it, and A330 has very comlicated VC definition. So for example when i wand to change smth in autopilot, i must turn on main panel. After all it's still beter to fly on VC. If you want i can send you a screenshot.