To Spazmelda:  I would say that yours is still an SX-150.  It is definately styled like one.  But there are a few mechanical differences in the shifting and the ribbon mechanism, as well as the spacing.  They've reduced the number of parts in the shifting, but it feels pretty much the same.  The spacing has also been simplified.  But the ribbon mechanism--now that one's totally different.  It uses a gear off of the escapement wheel, goes to the other end with one of those ball-type chains, and that drives the ribbon mechanism.  It does work and has been highly successful in their Underwoods including their touchmaster 5--or Underwood Five machines (not the old-style smaller black Underwood 5--these are the 1960s automatic tabulator grey monsters).  But, back to Golden Touch--I've seen a green Underwood portable Golden Touch, a green Underwood upright Golden Touch, and a green Underwood electric Golden Touch.  One of my biggest regrets here was that I only bought the upright manual and not the portable or the electric.  Waaaaaahh!!!

Yes--they slide side to side instead of lifting up like the 150s and the Golden Touches did.  Underwood Touch-Master Fives are identically equipped to the Touch-Master IIs.  You should still be able to find one here or there with ribbon covers.  To take them off, just squeeze the tracks there on together a little bit and pry up.  They should just snap on in installation.