Now cleaned up these lifters and found that internally they are completely different.

The unmarked INA ones have the outer reservoir then an internal bucket with an inner spring and an outer casing.

The marked ones have the same reservoir, but an internal bucket with both an internal spring and a spring which sits between the bucket and reservoir.

Never seen these sold as 2wd or 4x4 but it would seem the marked ones are a later version as fitted to the 4x4 but both are interchangable.

Therefore when changing lifters go for the marked ones as they appear to be a better design preventing start up rattles as the outer spring pushes up the lifter from the reservoir preventing it sticking and/or hydraulicing

Be interested to hear if the traders can confirm this.

Gareth - not sure yet, the master plan is to get it road registered for daylight use and use it as a track day car