The most useful fact for dating one of ours: we did not exist before 1964. Anything older that looks like ours is something else.
We were founded in 1964. A lamp carrying our name cannot be older, whatever the style suggests. We build them to look nineteenth century, and they do it well enough that people date them by appearance and land a hundred years out.
So the first question is not how old the lamp looks. It is whether our name is on it at all.
Check the base of the reservoir, the burner collar, and any surviving box or label. Our markings on glass are usually faint moulded lettering rather than printing, so hold it at an angle to a light.
If you find W.C. Bradley Co. on the packaging or paperwork, that puts the item at 1998 or later, because that is when the acquisition happened. Our branding with no parent company reference is weaker evidence, but it leans earlier.
Plenty of our lamps carry no marking on the lamp itself, because the branding lived on the box. One bought in the 1980s and used since will usually have nothing left to read.
We carried the model numbering across the ownership change, which is convenient for owners and unhelpful for dating. A 411B chimney fits a chamber lamp regardless of which decade the lamp came from.
What the parts do tell you is whether the lamp is ours at all. Our chimneys use a 2-5/8 in or 3 in base opening, and our wicks are 5/8 in or 3/4 in wide. Measure the chimney seat and the burner slot. Numbers outside those two pairs mean another manufacturer, and no amount of Lamplight paperwork changes that. Every measurement is tabulated in our parts finder.
We never ran a serial system on these, there are no date codes moulded into the glass, and our factory records are not public. Anyone offering a confident year for a specific mass-market oil lamp of this type is guessing.
What you can establish is a range: after 1964 if it is ours at all, after 1998 if the parent company appears anywhere on it, and roughly current if the packaging matches what is on sale now. That is as far as the evidence goes.
Clear-glass chamber and hurricane lamps came from dozens of companies, several of them supplying the same hardware chains we did. Shape alone proves nothing. The reliable separators are the fitting dimensions above and any surviving printed marking.
Genuinely antique oil lamps, the ones from the 1800s, differ in ways you can see once you look: hand-finished glass with visible seams or a pontil scar, brass with real wear rather than plating loss, burners marked by makers who appear in collector references. If none of that is there, the lamp is modern, ours or otherwise.
Rarely, for ours. One of our lamps from 1975 and one from last year are the same object in the same condition bracket, and the market prices them that way. Age drives value in oil lamps only once you are into named nineteenth-century makers and decorative glass, which we cover in our value guide.