question about Juan Volmerr Palmera tangs

i noitced some are "lasered?' and some are stamped... was this just a change to their processes with modernization or is there some explanation

SOme of those you are noting as laser marked were probably etched with a stencil. Volume and cost were probably considered in the cost. Stamping cost more for the tooling but is the quickest. A laser is probably more expensive but can be jobbed out to another company for the markings. Etching is the slowest, more labor intensive but cheapest in tooling and a good choice for low production runs. Just my guess w/ a machining background.