Back to the Future RPG Part II - Multiple Martys

So I've decided to go with the multiple-versions-of-Marty route for my Back to the Future RPG game. The reason being that I think it'll make for a really fun opportunity for players to all be Marty Mcfly, but have different abilities that are emphasized (and costumes, of course). The explanation for multiple Martys I'm still working on, but is going to involve a lot of technobabble and bad science, you can be sure. Essentially I'm going to say that, due to a quantum flux microcosm singularity, all the Martys that have ever traveled through time will come into individual existence at the same moment in New Time(tm). And will have to work together to find a way to fix things.

Obviously having everyone play the same character would get a little boring, and require me to set up encounters where five individual hoverboard races have to happen, which could get a little ridiculous. With that in mind, I've decided to push the questionable scientific babble even further and say that the individual Martys that split off from the main Marty became partially combined with their timestream counterparts, so the diffferent Martys will have differing skills based on their 'time theme.'

I'm still working on it, but here's what I'm thinking so far as far as primary abilities to emphasize when I make up the pregenerated Martys:

1985 Marty
- skateboard skill
- driving skill
- videocamera and headphones
- guitar

Return-to-1955 Marty
- Walkie-talkie
- Leather Jacket, hat, sunglasses
- Stealth skills
- Mechanical/sabotage skill


2015 Marty
- Hoverboard skill
- Self drying jacket/self-lacing shoes
- sports almanac
- hoverboard

Alternate 1985 Marty (Biff's Casino)
- tougher than other Martys
- bluffing skill
- baseball bat
- lots of money

1885 Marty
- trick-shooting skill
- horse-riding skill
- western clothes
- colt peacemaker


I'm considering giving all the Martys trick-shooting or frisbee skill, but I'm not sure how to differentiate them enough to make it work. Also, Marty shows a lot of promise doing trick-shots, but he can't bring himself to shoot an actual person, so...a potential flaw, perhaps?

I'm thinking 2015 Marty might start with some fancy futuristic aspirin or something for healing the party. Alternate 1985 Marty is clearly the front-line fighter (remember in this game he's partially combined with the Marty that grew up in alternate 1985, who grew up under casino-Biff's thumb). Western Marty will likely be the ranged guy, and Return-to-1955 Marty would be the stealth/thief guy. That leaves 1985 Marty to be the Wizard character...but how...

 I got it! He belts out face-melting solos on his guitar!

I'm sorry son, I'm afraid you're just too darn loud.

I think this is coming together. Man, that's heavy.