There has apparently been some confusion over that name through the years. There is (1) a gent in (FL?) that owns a co. with that name. Their product of the same name is a very dense fatty fluid that is used for supposedly softening up “cardboard hard” leather. I have my personal differences over that claim, but oh well … They also sell a product called “Pristeen Clean” used to clean the leather before (or after treating) with the Leatherique product. (to me, that stuff looked and smelled just like Formula 409 cleaner, btw) Then, there is (2) another co. that (used?) to have that same name based in the UK, which sells dye products for the inside of cars, particularly those of Brit origin. Eventually, the co. changed its name to “Gliptone, Ltd.” (hmmmm I wonder why? ) The co. had a dye product called “Scuffmaster”, which originally came in a small kit that included color-matched OEM dye (e.g. “Jaguar Doeskin”), a small foam applicator pad, and tiny twin eye drop bottles of “lightener” and “darkener” that could be added to the dye to more precisely match the color you need, to compensate for sun fading and such (you could also send them a swatch and they would match it at the factory). I loved that product and used it on all my Jags. Unfortunately, that co. was bought out several years ago and no longer has the Scuffmaster kit in their product line (and yes, I complained loudly to them about that, to no avail).
Having now been experiencing hardened seats in Superblue, I decided to go with an off-the-shelf product I had heard about many years again - Lexol. It is similar to Leatherique, and it has a companion product that, like with Pristeen Clean, is used to clean the leather before application or to remove traces of it after you have finished treating the area. I tried applying it to my passenger seat cushion in the hot summer sun and letting it sit all day with the windows rolled up. Checking things the next day I couldn’t tell the leather was one bit softer, though. I then suddenly remembered a “lesson” I had forgotten back when I was trying to soften up the seats in my XJ40s many years earlier, w/o success. As we discussed on the forum back then, apparently at the Jag factory the Connolly leather in post-'87 or so Jags received a coat of clear spray lacquer over it to act as a sort of “Scotch Guard” and protect it and help lengthen the life of it w/o cracking. THE MENTIONED LEATHER SOFTENER PRODUCTS CANNOT PENETRATE THAT LAYER OF LACQUER. In fact, IIRC, the U.S. Leatherique co. advised taking a piece of fine grit sandpaper and lightly rubbing the leather first to remove the lacquer so that their product could soak into the leather. They cautioned though not to “overdo it”, as leather which has been “roughed up” with sandpaper = suede. Since one of my XJ40s at the time was an old beater, I tried doing this and was still not happy with the end result, so I ended up tossing that co.'s products and have since then just put up with it through the years.