Quite a few smaller makers used to do this in the 20s and 30s - the one that immediately comes to mind is F H Grubb.
Hilary Stone, in sunny, still summerish Bristol, England
ben kamen wrote:
>
> whilst having a "butchers hook" through some stuff on ebay i noticed a CR
> period Poghlighi with the frame # stamped on the lower forward portion of
> the headtube lug. i have never seen this before and i think it looks super
> neat and doesn't look out of place or perhaps even adds to the character of
> the headtube decal (if one could say that about decals on headtubes).