I just bought this frame that has two hearts brazed on bottom tube . One near the headset that other at the crank . On the rear dropouts it says wccso . It is fairly light and dates around the 70's from what I can tell . It is lugged and they are close to schwinn lugs of that time period . The two hearts on the tube have got me stumped as they have original paint on them and around them . Any help would be appreciated.