You should be able to fit it no problem! It will be much easier to off-board wire the pot. Use the drill template on the Madbean
Baby Board Guide and you will be in business. Also, another good hint, use low profile film and electrolytic caps in the build, that will make getting the back on so much easier.
1590a isn't too much harder than anything else, you just have to make sure to think it through before you stuff everything in the box. You got this!