AXLE PAINT STAMP FONT

Hello Gents,
What is the name & size of the font used for stamping the axle assy number & date? What is the paint color? Thank you in advance.

The closest I've been able to match up on my 69 GTX is 5/8" Helvetica in yellow. Mine only had a three digit axle code, in my case "596". Hopefully, someone else will confirm the font.