TX 200 stock change

[Harves]

When did Air Arms change to the new stock design? Was this with the introduction of the MK III or did some MK III have the old style stocks?
It is my understanding that the MK III rifles have 3 hash marks on the receiver bolt.

[Roadworthy]

I have no idea when stocks changed.  The three "hash marks" on the compression tube correspond to the lockup on the anti bear trap.

[Jeff Marshall]

When did Air Arms change to the new stock design? Was this with the introduction of the MK III or did some MK III have the old style stocks?
It is my understanding that the MK III rifles have 3 hash marks on the receiver bolt.

The Mk II has three equally spaced notches on the compression chamber, the MkIII has unequally spaced ones.

MkIII's have shrouded barrels, MkII's don't.

Many  MkIII's were made with the old style stock (with regular checkering instead of fish scales).

Mk III's first appeared in late 1998, fish scale stocks were introduced in '06 or '07.