So what are the differences between the different arcade versions?
It's been a while and I may be wrong on some points, but here's
the breakdown:

Version 1:

• Zangief can SPD through EVERYTHING! Zangief can SPD outside the range of Guile's crouching forward leg(it's shorter I think). Zangief can SPD outside the range of Chun Li's Lighting Leg (Yup-yup kick thing) and E. Honda's 1,000 hand slap.
• Zangief's jumping short hits every one of Dhalsim's standing attacks clean, without any trades.
• Guile's handcuffs, pose, magic throw, and reset moves work.
• Dhalsim's invisiblity will reset the machine, instead of turning him invisible along with his regular reset move.

Version 2:

• Zangief toned down, unable to do the stuff mentioned above.
• Guile's handcuffs, pose, magic throw, and reset moves work.
• Standing flash kick will reset the machine.
• Dhalsim's invisiblity and reset moves work.

Version 3:

• Exactly the same as version 2, but Guile's standing flash kick will work and not reset the machine.

Version 4:

• Guile's handcuffs, pose, magic throw, reset move, and standing flash kick will not work.
• Dhalsim's invisiblity still works and I'm not too sure of the reset was fixed or not.
• An easy way to tell this version is that all of Guile's Sonic Booms are one speed (medium) regardless of which button was pushed. All of Guile's flash kicks are one height (medium) regardless of the button pushed.

Hopefully some of you guys will find the info interesting and
hopefully it's correct for the most part. That was a long time ago . . .