$240.00…this is a modern day ad?
Yes. Apparently. Maybe?
There is a place called Wallace Metalwork in Kempton, PA, apparently re-using the Mephisto trademark. Their website is linked
here.
OP is in D.C., though, so who knows.
The original Mephisto (in Wallingford, CT from 1909 to c.1937) and the relocated Mephisto (in Hudson NY from c.1937 to at least 1980's) did sell caulking irons that were "guaranteed to be made under the hammer", and, I have to admit, it's a cool idea (irrespective of business sense), but obviously not cool to be slapping ads in a vintage tools forum with no explanation.
If the OP is hoping to generate interest among antique tool collectors for new caulking irons made the old way for modern prices, I think a better approach might be to start a discussion, preferably in the Mephisto thread, or even up in the Fabrication forum, or both, talking about his passion for smithing and attempts to revitalize the name and methodology.
EDIT: I didn't see this until
@PugetDude bumped it. Very odd.