You will not wear out that Quincy!!! Congrats on making an excellent choice for your compressor, that thing should do the job but you will probably need to use a small nozzle, about a 1/8" or even smaller.
Now about sandblasting that cab, you are aware that you can very easily destroy it beyond repair by sandblasting don't you? I don't mean "well shucks I got a lot of work to do fixing that" I mean "take it to the scrap yard" kind of damage! Sandblasting a cab can be done but unless you understand exactly how to do it then it very well could result in irreparable damage due to sheet metal distortion. This is because the sand hitting the metal has a peening effect like millions of tiny hammers hitting it and it will cause the surface of the metal to expand causing massive warpage that simply can not be repaired. This is not, as is sometimes thought, due to heat from the blasting as the surface of the metal does not get hot therefore taking steps to keep the metal cool while blasting is useless and warpage will occur anyway. The effect is also cumulative so each pass will add to the problem and taking quick multiple passes will still cause warpage unless extreme care is taken.