would the bottom of a tool being "grounded" make a differnece in the time period and classification, also would common tools have been knapped for either a right handed person or left, on the same tool?
We have found very unusual items lately and have been trying to classify the types. Thanks for any information or ideas.

Alot of paleo artifacts have basel grinding they are some of the oldest point types

Good Q, I suggest you look for L & R diffences in subtle ways that the maker might not even realise that he is making something slightly different....

Here's an example for all those reading this can try at home...
When holding a good quality NOLAN with the point away from you, the base bevel is always sloping down on the right side. After some years of findings, I looked at one I just dug and it looked "weird" ~~ the bevel was on the left. I have found only a couple more like this at various sites, I'd call it like a one in 30 happening.