The Staccato bass is something quite interesting. They were cast using magnesium alloy and were built in Norfolk, England. The MG model which Gene played was introduced in 1985, which means that Gene was very quick on the draw in getting one, and it retained the cast magnesium neck but had a fiberglass body. The MG was also the first model from Staccato to move away from the concept of interchangeable necks and was built with a set neck. According to the Staccato web site the chrome-plated version with EMG pickups was a custom job for Gene. Note that this particular Staccato has two J-style pickups, what appears to be two control knobs, a front output jack, and the tuning mechanism at the bridge (which was the default for Staccato basses). The first sighting is in Providence 85.11.22 but it also makes a guest appearance in the high-brow concept promo for Uh! All Night.
 
Looking a little more image-compliant the same Staccato shows up in the promo for Crazy Nights in 1987. The video below is taken from the uncut reels of Gene closeups from the shoot (a mind-numbing watch should anyone care to track them down) and the twin J-pickups are clearly visible. This version also shows up in a few promo pictures from the day and there we clearly see the two control knobs,a mini switch and a front output jack. However, by the time the band were shooting the pics for the tour books this bass has been modified so that the "neck" pickup is switched for an EMG humbucker. (Notice what appears to be an extra frame around the pickup to cover the wider hole from the original J-style pickup and the lack of tuning pegs on the headstock.)
In total there were just over 200 model MG's made between 1985 and 1987.
The Staccato that got to see action on the road looks like a different bass altogether and that is in fact what it is. This one has Gene's usual bridge cover which means that the tuning bridge is probably gone and in its stead we find tuning pegs on the headstock. There's also a single EMG humbucker, a single volume knob and a side output jack. This seems like too much work considering the fiberglass body (although it is of course perfectly possible) but the "damning" evidence are the 12th fret markers on the neck. Remember, the necks are no longer interchangeable on the MG model and the Asylum/CCN Staccato has three dots at the 12th fret while the touring bass only has two.

 
 
The Staccato falls out of favor after the Crazy Nights tour. With the image move towards a more rootsy, rock look (no more sequins, bike reflectors, or colorful spandex) it would probably have looked a little odd next to Paul and Bruce playing Les Pauls. It is briefly brought back for a single photo shoot during the Revenge era and gets to feature in an ad for GHS strings before disappearing from the scene.
Note the location of the strap "screw-in loop" as favored by Gene in later years. This is a late addition that isn't seen in the Crazy Nights pics above.