Yes, and no.
If you're going to look at current California law. a semi-auto M14/M1A w/o a "flash-hider" or other qualifying features is legal to possess, something that would be similar to this rifle:
[qimg]http://imageshack.com/a/img34/1813/hbp6.jpg[/qimg]
While the same exact rifle in this configuration:
[qimg]http://imageshack.com/a/img856/899/rcyz.jpg[/qimg]
Would be illegal if not registered as an "assault weapon by features" under the second round of Ca. AW laws.
Most of the designs listed by name and model in the original California AW law, the Roberti-Roos Assault Weapon Control Act were the then currently available semi-auto only versions of both battle rifle types (M14, G3, FAL, etc.) and assault rifle types (AR platform, AK) and pistol caliber cartridge carbines based on common SMG type designs (Uzi, HK MP 5, Sterling) All of these types started out in the basic configuration that were eventually sold to civilians absent certain mechanical features and barrel length, but outside of adapted variations on the AK platform and the standard rifle configurations of the 14 platform, none of these are adaptable to a standard rifle or carbine configuration.
What is important to note is that at least in the case in California, there are rifles on the ban list that most folks, including firearms collectors and LEO's have never seen outside of a photo, and have never been used in a crime - here's a few:
Spanish CETME from the mid 1960's:
[qimg]http://imageshack.com/a/img196/7824/9y42.jpg[/qimg]
[qimg]http://imageshack.com/a/img42/3424/vynu.jpg[/qimg]
SIG American Match Target:
[qimg]http://imageshack.com/a/img547/7783/sswq.jpg[/qimg]
FN G series FAL:
[qimg]http://imageshack.com/a/img59/2383/3g5e.jpg[/qimg]
Australian L1A1:
[qimg]http://imageshack.com/a/img560/9252/n6wz.jpg[/qimg]
The rifles above represent a class of firearms that politicians (as you noted) banned because of how they appear in their eyes - the fact that none of the rifles above have ever turned up as a crime weapon (a function of price and rarity, there were only 153 Aussie L1A1's ever imported, somewhere under 2000 G series FAL's perhaps 1500-1800 AMT's and similar numbers on the MARS CETME) and were essentially unavailable in 1989 (only the Aussie L1A1 was a currently available rifle, and in that case 153 examples isn't a mass market commercial product) had -0- influence on the legislators involved, it looks scary, on to the list it went.