There are lots of line on the battery side of the tractor.  I would have someone operate the tractor while you watch the right side, with the battery tray open, I bet you find it quick, and it probably won't be all that hard to fix.  These older tractors tend to wear through steel lines as many times maintenance in the past didn't get the lines put back in exactly the right spot, or missing line isolation/rubber parts.  Sometime a quick drain and braze, and you are back in business.

First of all and foremost, it is YOUR operation, and you need to do what you think is best, but I would throw this out there.  Your loader combination is not overkill for those tasks.  Moving bunks, hauling manure, loading hay, etc. etc. etc. would be either slow or pushing the limits of smaller Kabota sized or D17 sized loaders, and yes the cab makes a huge difference in the winter.  I am not saying it can't be done in a smaller loader, as it certainly can, but I imagine if you asked every owner of an operation your size, that owned a smaller tractor loader combination, many if not most would tell you there are many times a bigger loader would make a difference.  Given what the smaller newer tractor loader combinations cost these days, you may have less money into what you have, and have the convenience of the bigger rig, not to mention if it really is overkill, you should never break it.