I have had an old Stanley h13b builders kit for a while that I am now hoping to fix up. The push to lock shaft button is currently off of it. I have the button itself and what looks like a spring for it, but it looks like there is something else missing to complete everything. Does anyone know what goes in this assembly or even better know where I could get the part? I'm fine with fashioning something new, but knowing what it is I am replacing at least would help a lot. Thanks much for any help.