All About Pocket Knives

a friend showed up with this the other day...had been run over and thrown in a tool box for years...what is it?
solid aluminum, milled then plated, suggests a fine piece at one time? is it german? a paratrooper? i thought it was a gravity knife, but wear patterns suggest a more forceful exit of the blade...

is it worth fixing? perhaps for the practice...scales is not a big deal... welding the one side back together is not a real issue...but what parts went into the trigger? what type of spring?

duh?

that looks like an italian version of the american "slider" most commonly used is the USA as an advertising knife, looks like the button/spring mechanism is missing, probably broke off and/or lost over the years here is an american slider I did for Singin46

thanks muskrat...