I haven't really been answering these sort of threads lately but I'll take a stab at it since nobody responded.
I don't suppose he knows the origin of the cue or the chain of ownership? So I would guess it's a 1960's era based on the way the ivory butt is configured. It's a typical Titleist conversion and it looks to me like Rambow himself did the lettering (others were lettered by a calligrapher). Probably closer to the end of his career than the beginning.
If this cue belonged to James J. DeCesari, he was a reputed gangster tied in with the mob in Chicago, where Rambow had his shop. See "Juries Probe Mob" in the link below - James DeCesari is gambling figure from the south side linked to the Chicago syndicate.
http://archives.chicagotribune.com/1970/04/21/page/14/article/juries-probe-mob
It's not a very common name, the age was right (50 years old in 1970) so I think there is a very good chance this is him. Also, with the initials James J. DeCesari, it goes along with the shaft lettering, so it most likely is the guy.
What helps the value is the ivory butt and "made by Rambow" lettering, which does not always appear on personalized cues. What hurts the value is the abundant black marks on the cue may never come out. Those are from storing the cue in a case with a black dyed lining and the dye was transferred. The stuff goes pretty deep and is likely well into the wood.
The value of the cue is likely in the $2,000 to $2,500 auction value range and I would say it's in average condition based on the pics.
Now all of this may be true, or none of it may be true. Likely none of it can be verified. I am just looking at a picture of a cue and my mind just wanders and wanders...