Lost oil filler cap - did do any damage?

as long as you didn't blow the oil out, it should return to normal now that the cap is back in place.

You were VERY fortunate indeed! The oil cap must be been just on tight enough for most of your journey of 450+ miles. Had it worked it way loose or knocked out of place due to oil pressure, you just might be looking at a seized engine and the prospects of having to buy a new one.....Almost happened to my GF when the idiot mechanic forget to put the oil cap back on after an oil change some years back...oil pressure forced most of the oil out all over the engine...The store manger & service manager who were BOTH fired not too long after that, agreed to steam clean the engine and replace the oil for free (of course)..but no damage with the engine..Thank God!

Thanks for your help. Oil level fine/clean. There is a defector baffle that might have helped keep oil in? I won't do that again! lol