Maybe Trench Art isn't the correct term as trenches were out by WW2, but this seems like a pretty cool little item, and only 23 dollars US with 2 days to go... the description says..
"Original Very Rare WW2 Vickers .5 Machine Gun Bullet Lighter in good used condition and full working order.(see photos) Lighter is engraved to Commemorate the first Vickers .5 Machine Gun Made in Canada. Completed October 30 1942. First fired November 2 1942. Lighter is three and three quarter inches tall. The .5 Vickers was a larger version of the .303 model. It was used on armoured vehicles and tanks. Also on Naval vessels as anti aircraft guns and motor torpedo and gun boats. I do not know what the O.C.&A. stands for but it could be the gun manufacturer here in Canada. If any one knows, feel free to e-mail. Thanks'
Update: Lighter brought $68.67