Source: DC Heroes Role-Playing Game 1st Ed. (1985), DC Heroes 2nd Ed. (1989), DC Universe RPG (2000), DC Adventures RPG (2011)
Like most ordinary humans, he's a series of 2s (average in every category), with 0 Hero Points (oh come on!), and the subpar skill of Detective rated at 1. Eeech. Jimmy fares better in the Superman Sourcebook, where his Elastic Lad identity is taken into account, boosting his Dexterity to 4, his Body to 3, and giving him Stretching 5, albeit only when he drinks from that special potion. Detective is now rated at 2, with extra skills like Artist/Photographer & Writer 3, Charisma/Interrogation 2, and Vehicles 2. He has 20 Hero Points to spend and finally gets a Motivation: Thrill of Adventure. Plus, access to a Flight Ring, but most importantly, a Signal Watch that calls Superman. That was a major omission from the original write-up! As this is really the Silver and Bronze Age Jimmy, I would have loved to see write-ups for Turtle Boy or other transformations. Alas. The book does include an Earth-2 (Golden Age) James Olsen, currently editor of the Daily Star, who is a lot more like that first write-up.
Cut to 2nd edition. The roster book from the main box sketches the post-Crisis Jimmy in, but does a much more thorough job of it. Most of his stats hover around 3, with particularly good Mind and Spirit. He has Artist/Photographer 3, Gadgetry 2, Thief 2 and 15 Hero Points, as well as Connections to the Daily Planet and Superman, as well as an Irrational Attraction to curiosity. You can see the mechanics here define the character much more. The Signal Watch is there, of course, and his Motivation has changed to Upholding the Good. In the Superman The Man of Steel Sourcebook, it switches back to Thrill of Adventure, but give or take a small tweak here and there, the designers haven't changed him.
Looks like the DCU version is the most accomplished, but if I were to play Jimmy, I'd start from scratch and put in everything I could, including a "weirdness magnet" disadvantage that would make sure I get dosed with Turtle Kaiju levels of radiation or fall into the time vortex on a regular basis, an Archenemy Romance with Lucy Lane, the cross-dressing chest of many costumes and the Flying Newsroom in my equipment, and stats inspired by Kirby's run on his book. Damn. Now I want to play this very badly indeed.