I don't know a ton about the Mini 14's, there's probably some experts out there, but the GB models were government models with a bayonet lug and flash hider directly from the factory. GB models were also made in a full auto version called the 556, though the GB's and 556's were never officially adopted by any military... other than the A Team. Lots of police adopted the GB versions and hence they were stamped LE and had 2 serial numbers, one 18X, and one 550. The GB is the exact same gun, just for "LE", no more accurate than the others. If you're into sentimental and historic values then you may be willing to pay more for them.
The factory wooden stocks were sold by Ruger to people who could provide the correct pre ban serial numbers as recently as 2002, maybe they still do but I'm not sure. They fit series 181 to 186, meaning guns produced from 1978 to 1999. They were offered from the factory to civilians at least until the 94 assault weapons ban, but since Ruger's infamous "high cap mag" letter in 1989 I have a feeling they may have stopped selling them to civ's before 94.
The stocks are worth a pretty penny, here and in the USA. The last factory stock was sold retail in Canada three months ago... to me! For... drum roll please... $275! I know because I contacted almost every store coast to coast. They sell on Ebay for upwards of $500US, as you've seen the complete guns will sell upwards of $1100.
In my opinion they're just plain cool, ugly as hell, but friggin sweet. The top SS one with the Leopold scope and sling was my old man's, mine now, series 184, 1985 produced, with a factory 20 round mag, the bottom blue one was acquired by me, series 183, 1983 produced, with an aftermarket 30 round mag. They both sport aftermarket flash hiders. I've got a thing for the factory folders, I don't think I'll ever sell them, I have a dream of having a whole rack of them one day!
People who complain about the accuracy problems don't realize the gun was made to be a die hard trooper, modeled not only after the M-14, but the SKS and AK-47's gas systems too. The gun's are reliable, no doubt about it, go bury it in the back yard and dig it up a year later and shoot away. It shoots accurately enough out to 200, you can accurize it if you want, but people are under the impression Ruger is advertising them as sniper rifles, which they're not. They're supposed to be economical assault rifles that aren't "scary" looking and won't fall apart on you, which is why they're not restricted in the People Republik of Kanada, unlike the precious AR-15's...