It is normal for a older engine to burn oil. My 1152 had worn rings and a failing rod change oil seal and it was not uncommon for me to top 500Mls of oil every 2-3 weeks (approx 150 miles) and I don't classify this as excessive.
The manual says something stupid like it can drink up to 1L of oil every 1000miles or something like that
At the end of the day if your engine has done 50,000+ miles it's tired and you would expect it to seep past the rings, seep past the valve guides, drip here and there. It all adds up.
Check your oil level as often as you can, takes 5 secs to do, and you can then get an idea of how much or how little your engine is burning. Check before a long drive, check the next day after that long drive to see what "dammage" has been done.