Rehash, clarification, speculations and some "ass"umptions.
16" barrel, standard gas, type 1 block is what's pictured.
Type 0(gen 1) gas block needs a wrench to loosen a nut in order to lift then turn the gas regulator to one of the 4 positions. The rest of RA gas blocks don't require anything more than a bullet tip.
Type 1 and Type 3 blocks use the same piston head. As long as the gas length is the same, it's a direct swap.
Type 0 is a specific piston head that only works with the original style op rod. Any of the "lite" versions or without a welded foot won't work.
Type 0 and 1 use the same gas tube.
Type 3 gas tube is specific.
If you want to use the above setup in a newer gun:
Swap out the old block for a Type 3
Or
Swap out new gas tube for a Type 1(no longer produced)
If you can't source a Type 2 BOLT quickly, I'm thinking you could chop the tail end of a Type 1 bolt off to make it compatible with the current style carrier and firing pin. I'm betting the 556 tail will still be fine for most of your shooting needs. Another member has run a Type 1 bolt in a Type 2 carrier without the Type 2 firing pin installed. I don't build guns for a living but it seems to me that setup significantly increases your chance of a OOB