The problem with the Turks or the Afghans theory is whether they actually had Ross Rifles to start with.
I'm minded to suggest that such a modification would be done by someone armed with Ross rifles, albeit in small numbers, who had a need for a bayonet. After all, as the old Army saying goes, if you need a bayonet, you REALLY DO need a bayonet.
So I am suggesting that the BritishHome Guard really needed bayonets. They certain;y welded old bayonets onto steel scaffold tube so why wouldn't they weld up bayonets to fit onto their Ross Rifles.
Maybe this thread should be transferred to the Bayonets section so it gets more air time