Looks like a 1992 Tufftrax, so yes fairly low end of the 'Off-Road Sport' range with a 400LX and Deore LX component mix. It would have originally been specced with Deore thumbshifters and brake levers too, which appear to still be there.
The forks, canti bridge, dropouts and top tube cable routing all point to a later 1992 production date. The colour and the 'Off-Road Sport' decal on the seat tube are a big clue too.
It also looks like the original Zoom stem rather than a Ritchey one as suggested in the listing.
The catalogue below shows an early 92 model, with different dropouts and internal cable routing. Early 92 models would have been built using elements of the 1991 range, leftovers if you will, such as the dropouts etc.
It's possible that this bike was sold as a 1993 model year bike towrds the end of 1992 or in early 1993. As such it could have been originally badged as a 'Limited Edition' which was basically a way that Saracen rebranded last years bikes and sold them as new models the following year to clear surplus stock.
If this is the case them it would not have appeared in the 1993 catalogue and would have been a 'dealer special' often built up with a strange mix of parts.
I can see why the seller may believe it to be rarer or more unique than it actually is. But in truth it' no more a prototype team frame than a Raleigh Mustang is.
It is however considerably better than a Mustang, in fact with a decent Tange tubeset it will be quite a nice little bike.
