Hi. Just picked this up and am trying to figure out the make and model of this frame. It's a steel frame lugged frame. Eyelets on rear and front fork. It has a cutout on the bottom bracket that looks like the letter Y to me but to my buddy it looks like a heart. There are the letters IS (I can't make them out) on the left side of the head tube lug and 74 and 60 on the other side. No other markings on the dropout. Oh yeah, the cool thing is it has an internal cable routing on the top tube.

Any info would be appreciated. Thanks!