my two cents
My understanding of this configuration,SKS-30round mag,Bayonet.
The SKS was only issued 1 year with 30 round magazines,there are alot of after market conversions(illegal) out and about attrachting unknowing buyers.You read about alot of feeding problems with the after market conversions.
The Bayonet was issued in the later production years.My Yugo 59/63 has grenade launcher,Bayonet,10 round fixed mag,and flash supressor.All original issue,legal to own in Indiana.
Now in the republic of California the Bayo is a no-no,and I bet that detachable mag could land you some prison time. Correct me if I'm wrong but Cali is the only state I know of which is Bayonet less-friendly.