Seiko 7A38 - by the numbers

Not being a watch smith or even a moderately competent amateur I decided to start by stripping a 7a38 I bought really cheaply for parts/practice. I've removed watch movements before, so removing the case back went okay. It was very tight though. Inside looked like something off the Titanic. Serious rust. I managed to get the movement screws out, but the PCB is totalled. So what should look to keep for spares? The case is staying as it's pretty good and a style I like. Maybe I will find a clean movement in a bashed up case and perform a transplant.