My oil burning pig. Pics too!

The Total Seal rings not working right is surely a possibility. But I used to completely blacken up natural petroleum oils up in 100 miles of hard racing on a couple of different type 4 cylinders, one turbo and one not with no real blow by. It was just the high heat oxidizing some components in the oil. (Reduced that hugely by going to synthetics.) I don't know how hard you hammered on it in your 81 miles or the heat in the engine or what oil you use and if it could have been effected that much. If mostly cruising, it's not likely just due to oil oxidization.

I haven't ever been able to see how bad rings would push oil up on top of the valves in this thread. But, ring blow by when you are on it hard could push oil past the seals/guides. I would suspect that more.

Sounds like it is coming apart; pretty much needed to happen at least partially to get a good read on the guides and you can put in some more appropriate rings, etc. I'd use moly top rings for their ease in seating; I'd expect your machinist would suggest that.

It would be crazy IMO to not check out the guides very thoroughly. Once a couple of springs are removed, it'll be evident.