[Dolalin]

I found another source that has pushed the timing back to November 1999:

11/3/99

I must make a quick note concerning banded gauntlet molds. They can now be found on all vendors that have banded armor molds and are now craftable in all sizes. Thanks goes out to all smiths who sent me information concerning this change.

http://web.archive.org/web/200006220...lacksmiths.htm

Edit: I just saw that there is an October 1999 mention in the patch notes that says blacksmithing items were added. Given the above, balance of probabilities says this was likely when Banded Gauntlet molds were put on merchants:

October 13, 1999

Trade Skills

- A number of new items have been added to Blacksmithing.

https://wiki.project1999.com/Patch_Notes#Trade_Skills