HPI nitro EVo Rush
 

Hi I have taken the old Evo out the loft, the engine seems to turn on however I am having issues with the carb, looks like the rotary arm for accelerating isn’t opening and closing the carb, took it all apart but it seems
like it is stuck and the screw at the top has snapped off also the bottom part that connects to the engine is slightly broken.
looks like. I need a new carb but hard to get it as all parts seems discontinued, I have found that some other engines are compatible was thinking of getting a replacement of eBay. How do I know what is compatible? And would anyone have suggestions what I should do?
would it make sense just to get the whole second hand engine?
thanks for your help