Nice! With some kit mods this set would also work for late WW1 I would imagine.

No need for a conversion. ICM also offers a World War One gun with crew. LINK

Although those smooth cooling jackets only appeared in late 1918, so you’d want a fluted job for most WW1 examples.

That would be a lot of mods as the uniforms were very different! Anyway, as G. O. says, there's no need.

Hmmm...ICM doesn't include any sprue shots, but I would assume they include the standard weapons and equipment sprue with optional helmets, if you want your crew to wear them.