Welcome. And the answer is here, and this is a good place
Mag safeties were decommissioned years before they went out of nazi service. A lot of military guns ended up in Vietnam, so not a huge surprise, but interesting.
Provide pictures and info, type, serial number etc and we can help.
Value would be from $500-$1600, all depending on if original, any extras (holster) mags, etc.
Capture papers help, but are not worth a huge amount, maybe $50-$100 extra.
Ed