Here we go. After some detective work I have come up with the following. As far as I know the dates are correct, but there may be errors.
Rear hub. Sachs 3X7. Made from 1994-2000. Sachs taken over by SRAM in 1997. Marked with "Sachs 3X7", so probably pre '97, though Sachs marked stock may have been sold by SRAM after '97. Previous owner stated it was on it when he bought it in 2001, and he had a 700C rim built on to it. It had no front changer or post, just the triple chainset.
Rear Derailleur is marked "Exage 500", made from 1990-93. May or may not be original, may have been from stock after '93. I would have to take it off and look at the back for more info.
Front triple chainring is marked Suntour X-1. X-1 available from 92-93. May have been from stock after '93. It ties in with photos of other Linears I have seen, some with Sachs 3X7 hubs and no front changer, and some with a front derailleur post and changer with no hub gear. The X-1 is fairly distinctive in appearance.
According to the manual the fuzzy picture of the rear brake shows a Dia Compe caliper brake. It must have had a long reach if the original wheel was 26", maybe even an Old School BMX brake? It now has an unidentified caliper brake which just has enough reach for the 700C wheel, presumably sourced from someone's bits box when the wheel was rebuilt to 700C.
The front wheel has a drum brake with no markings, alloy hub, steel torque arm, and a nice satin finish alloy rim. It is a 500A size, and from what the seller told me was on it when he bought it. It doubt it was an original option from Linear, probably acquired somewhere in its history. There are no V brake bosses on the fork, so probably originally had a caliper brake.
If as I suspect it came from the factory with a Sachs 3X7 hub gear it could not be earlier than 1994. If it was much more recent than '94 it might have more recent components. My best guess would be that it dates from around 1994-95.
It would be interesting to hear from other Linear owners who might know the vintage of their own bikes, and to see what components are on theirs.