T Reproductions makes 99.99% authentic replicas of original Buddy "L" toys. They either are licensed to do so from whomever owns the Buddy "L" name or plans, or can do so if the company closed down and no one bought the company after. I've never seen one up close,but I would assume T Reproductions have their own decal or identification marks somewhere.
Older and original nickel-plated figures (firemen) or ladders appear to have certain finish probably from age and human oils from the hands that causes them to yellow. Newer replacement are shinier and silver-toned. As well, the new parts may not be nickel-plated.