Originally Posted by
vintagerando
Well....whats a "no slide pib"? I know you are referring the down-tube, but a "pib"?
frames sometimes have a little button of sorts brazed on to the downtube in order to keep the shift levers from slipping downward. it also means shift lever clamp does not need to be so tight as to damage tube. the underside of the tube is not shown in the photos, hence the question. presence or absence of pib and its shape are one more tiny clue toward possible identification.
"no-slide pib" is British jargon. dunno if there be a yank equivalent.