Thats pretty nasty!
The malossi shorty you might need to shave the top of the flange a little to get it to bolt on. You will see what I mean when you get it if it is the one that needs a shave.
You will want to derestrict the exhause or at least make a new back plate with at least a 11mm or 7/16 exit hole for the full experience. Without the backflow silencer it will be louder but the original is restrictive.
With all that crap in the carb you would also want to flush your fuel tank really well with some kerosene. Also check if your fueltap is working.