The regular SKS, which does not have a detachable magazine, is not a regulated firearm in Maryland. But unless you have a C&R license, you will still have to have it shipped to an FFL dealer in Maryland. You will have to send a signed copy of his license along with the money.
BTW, the bill mentioned did NOT pass, but the sponsors are probably out hiring a couple of more beltway snipers, so it will be back next year, worse than ever.
Just to clarify. MD already bans the sale (but not possession) of a bunch of named "assault handguns" (Tec 9 and the like), and purchase of any of a list of named "assault rifles" has to go through a waiting period and approval by the state police same as a handgun. The defeated bill would have required registration and banned the sale of all semi-auto rifles with detachable magazines (the wording on evil features was deliberately fuzzed, but that was the intent).
Jim