Definitely pack your own shoes.
If your shoes have the old fashioned metal spikes on the bottom you can unscrew them and pack them safely, so that they won't tear any other clothes in your bag. Any Pro shop will screw them firmly back in for you.
If you use the soft spikes there isn't going to be a problem.
New shoes or borrowed shoes never feel right.
BTW think hard about not playing the old course, it may be the only chance you get. We pass this way but once !
In both Scotland and Ireland ( and anywhere else in the civilised world ) the best information on courses is to be found in a friendly bar.
There are three courses within half an hour of where I live, all of them are real honeys, but they never get a mention in any of the golf magazines. It's the same in Scotland and Ireland, there are beautiful courses that only the locals know about.
Have a wonderful time.