An original aluminum crankshaft pulley from an XK150 part number C7275 this was also fitted to the MKVII and XK140 & the MK1 but obviously check compatibility before committing to purchase.

The part is used and does show some evidence of wear but it's not bad for a part that is about 60 odd years old.

OK to use but if you wanted to take it to the next level it will need vapor blasting etc.