Affordable repair service?

I recently bought a set of air horns for only 20 bucks because they do not function properly and figured it would be worth it if I could get them going. They are the typical 3 bell eBay type horns that are passed off as train horns. When I run air through them they produce noise but it doesn’t right at all compared to mine which are basically identical. I was wondering if anybody knows of a way fix them or somebody who could do it for cheap because I don’t want to put a lot of money into them.

Also, If I can get them sounding right do you think 150psi is enough to power both of them at the same time? I understand they will drain my tank twice as fast, just figured two would be better than one. The line is only 1/4 I believe.