Whatever you choose, you will have a high quality knife to use or collect.
With old knives, there are a LOT of fakes and used/rusted knives that are buffed to a high shine and sold as new. There are also a lot of heavily worn old knives. If you find a 1970 or earlier knife that is truly all original and truly well preserved (not buffed), they are very nice knives.
Finding an antique sowbelly from Case that's original and in good condition is very unlikely. And it would likely cost a ton of money. But in my opinion, the current production of the Tony Bose pattern is high quality. So if you want a sowbelly to use, the current production should serve you well.
On the other hand, I greatly prefer the 1970 and earlier 32 pattern stockman compared to the current production 032. And they are common enough that you should be able to find an old one in good condition.