Just a thread bump.
I have an older Matco box with lock no. MA56. (I think c. 1970's or early 80's). I had one key (I know I should've had a spare!). I no longer have that key. No success with locksmiths and the lock no.
Called Matco and they said I had to see a dealer. We've got no truck in the area, and any way, it seems like a real pain for both me and the dealer to have to bother with ordering a key through him. It kinda seems inconsiderate to bother a dealer over something like this. I'm surprised that Matco would suggest it and not have an alternative (like selling the key direct), esp. on older boxes.
Snap-On will sell you a key (or refer you to LDV for older keys) and it's been a pretty efficient means of getting replacements or duplicates for those boxes.
Anyone know if there's an equivalent to LDV for Matco or an on-line source for Matco keys?