You stole that package. Great deal!! I guess I'd start by taking the barrel off the frame and checking the number engraved or stamped in the underlug. If it came out of the factory as a combo, the numbers on both barrels should match the last 3 digits of the serial number on the frame. If they don't match, someone pieced it together.....not necessarily a bad thing. Check the FAQs at the top of this H&R centerfire page. The two letter prefix on the serial number will give you the year of manufacture. Also, the twist rates are there. Lot's of good info. Most Handi .223s will hit whatever the shooter is capeable of. Great find. Good shooting.
Pete