MOONCOON; as usual, you are 100% right. The chain of the Wheellock was the hard part to duplicate, it being a very tiny roller-type chain which was perhaps 1/8 or 3/16 of an inch between pins. Just TRY making something like that when your only tools are a big hammer, a little hammer, a file and possibly a soft chisel.
Today, of course, you can buy chain of whatever specification you like, some types just perfect for Wheellocks, at a couple of bucks a foot.
As to the Pyrite, this is where the Wheellock has one advantage over the Flintlock: in the Flintlock, the ignition sparks are produced by bits of hot iron beaten from the Steel by contact with the Flint. In time, the Steel becomes worn and needs to be resurfaced and re-hardened. The Flint, meanwhile, beats itself to bits and must be replaced. The military used to count themselves doing well to get 30 rounds out of a Flint.
With the Wheellock, what was being eaten away was the Pyrite itself. Iron Pyrite (Fool's Gold) is FeS2; you can heat it up, drive off the Sulphur and you are left (in theory, at least) with crude Iron. Without modern furnaces, the Iron won't be much good, but it can be done on an industrial scale. But it was the actual Pyrite which provided the sparks and it wore away quickly due to contact with the serrated and hardened edge of the Wheel. Good Pyrite would give perhaps a dozen shots; much wore away even faster than that.
A Lock which would bear investigation is the Piper Lock. As far as I can find, it has never actually been manufactured, although it was described fairly thoroughly in his fiction by noted firearms authority H. Beam Piper. Piper was born in 1904, largely self-educated and a very fine writer of well-conceived action fiction with a lot of thought behind it. He died in 1964, death by suicide caused by poverty and depression. Piper wrote of this distinctive lock in several stories, the most noteworthy being his final novel, "Lord Kalvan of Otherwhen" (1964). As Piper described the beast, it was a wheellock without a wheel and without a chain, using a SEGMENT of a wheel and an Arm holding the Flint to the serrated edge of the Wheel Segment. The action was much like the striking of a #### against the Steel of a regular Flintlock, except that the Wheel Segment was attached to a Tumbler, much as the #### of a Flintlock. The Wheel Segment bore against the Flint on its Arm. When the Trigger was pulled, the Sear broke clear of the Tumbler as in a regular Flint or Percussion lock, avoiding the lateral Sear with which regular Wheellocks and the earliest Flinters were fitted. The Wheel Segment then did its quarter-turn tumble against the Flint, showering a steady stream of sparks into the Pan. Such a Lock would be simple to fit with both a sliding Safety and an automatic Pan Cover, thus providing a holster weapon with ALL the advantages of a Flintlock AND all the advantages of a Wheellock WITHOUT the expense. When we get the last of the machines moved into the workshop at Janice's little castle, I think it just might be fun to build a Piper Lock.
It bears investigation, if nothing else.
Legally, it is a combination of the better features of a Wheellock and a Flintlock. I really cannot see it as being restricted.
Hope this helps.
