Wood stocks came on the Trooper Mark V which uses the same grip frame as the later King Cobra and Anaconda. Some special editions of the Anaconda came with the same wood stocks but most production came with the rubber type. Colt did sell the wood stocks aftermarket on a shrink wrapped Colt card. I wouldn't be surprised if someone had a special order Anaconda the wood stocks could be specified.
What Colt used to do when they hand fitted wood stocks to their revolvers the person doing the fitting would write the last several digits of the gun's serial number on the inside of each panel. Whether that was still being done by the time the Anaconda came around I can't say for sure but I doubt it as the stocks completely surrounded the frame rather than fit along the grip frame.