It might be of course that you are trying to fix a problem that doesn’t actually exist.
I was a little surprised to find a lack of valve guide seals on my own bike (a 350) when I stripped down the cylinder head. It had only covered 3,000 miles in the first 13 years of its life with four previous owners but had a soft exhaust valve seat and kept losing compression. However, I was also pleased to see how well the valve stems fitted in the guides and decided to rebuild it as it came, i.e. without guide seals. It doesn’t burn much oil, actually less now I’ve put another 10,000 miles of hard riding on it and removed the breather catch can. I don’t think it was fully run in before I bought it.