Seatpost size of 26.8 indicates that the frame is probably not one of the lighter steel framesets around. 27.2 seatpost size is used on the better, thinner steel framesets (this was true from at least the 1970s til present). This frame might be fine for you, but it's weight might be on the heavy side - ask or weigh it if you can. Also, it may be a somewhat stiff frame - it may not have butted tubes (tubes that are thinner in the middle than the ends). So much information conveyed by seatpost size on a steel frame...