Help choosing between two frame sizes based on my dimensions
When in doubt, the best is to try the bike.

Dimensions are important from an anthropometric point of vue especially to prevent injuries and such. So in that perspective if you're kind of in-between sizes the choice will be guided by your sensations. 

I know cyclists that prefer oversize and others that prefer undersize, it depends on how much you lean on the bike and that kind of factors. 

So the best way to do it is to spot the extremities on your size spectrum and try bikes that match, you will feel what is natural for you.

I personnaly ride an old steelframe oversized roadbike and it's feels awesome.