Just a tip from an engineer.
Never dump a text book especially anything to do with engineering. You will never recover its true worth and you also never know when you might need it again. Engineering dosn't change, most of it has been known for hundreds of years only the method of application and operation will change.
Yes you might pass instruments but remember that you will again have to tackle the subject for MCC, job interview, sim check, type rating, reference for your line training, then use every 6 months when you need to check your facts while discussing something on pprune.
I hadn't opened my thermo/fluid mechanics books for nearly 4 years before i started the ATPL exams. As they are the same books that my father used for his physics degree 35 years ago i think we are just proving how tight arsed Scottish and Yorkshire engineers are.
If you still want to sell it in a couple of months just give me a email and i will take it for 20 quid.
MJ