M-10s are so cute but need a better stock
here is what I did for mine.
How to tell if full auto. on left side of frame there will be a full/semi rotating selector. From the wear marks you will see that chances are this gun was never taken out of the full position.
For a while open bolt semis demanded more money than a registered full auto since they were so easy to convert and some valued this over the registration process. Well the registered ones have finally become rare enough that they are worth more than the semis.