I am staring at an early 60's Paramount frame right now, "split" barrel guides brazed on to the underside of the top tube biased about "one hour" toward the drive side.
Frame is a friend's, only thing that looks modified possibly is the non drive side seat bolt ear has a brazed in fixed nut, looking similar to the back side of a Campagnolo chainring fastener.
I have to do some referencing for him on that detail.
John Jorgensen
Torrance Ca