If you get blue smoke on startup, and also at idle (but not during normal driving), then yes, it's most likely valve stem seals. I recently had this issue myself.
You can potentially change the seals with the head installed. You either feed compressed air into the cylinders to hold the valves up when you pop the locks off, or you fill the cylinders with nylon rope/paracord, which achieves the same result.
Because I don't have access to compressed air, I tried the rope trick, but it was impossible for me to pop the valve locks using a screw-type valve spring compressor - they were too well stuck. In the end I wound up pulling the head and getting a full valve job done at a local machine shop, and with your engine at 210k, that's probably the best idea for you as well.