I paid $1100 for an almost new long head with all the features (clean level pot plus gain trim switch).
You will have the latest if it has a rear-panel switch that lets you trim gain for Clean, HI/LO, or Normal (shown in the manual on the right side of the rear panel). This feature is critical.
There is no production short head. Originally it came as a medium or long head, then they stopped offering the long head. I see a lot of medium heads advertised as short heads. FYI, long is 27", med is 23". Yes, the 4" makes a difference for portability, as it's a HUGE head.
Swapping between head and combo is awkward, as the chassis is upside-down in one of them.