I am building Tamiya's Cromwell and Went to install parts D11 and D12. Their mounting holes have to be drilled out so I was wondering if those were optional parts. The photos I saw of Cromwells did not show those parts.

These two parts are part of a sighting system and you can see what it looks like on these two cromwell's and a comet. Most photo etch sets for the Cromwell offer this details as well.

IIRC these were part of a manual sighting system for the commander, and are not terribly visible in most photos partly because they were little more than wire and just get "lost" against a background of the TC in his hatch seen in so many of the period photos. They were on the gun tanks, but Tamiya uses the same sprues for the Centaur CS 95mm tank, which did not have these sights, so the holes are blind.

Thanks for the information!

Darren, your build has inspired me to build the Cromwell. I will post some of my photos soon.

Greg: I am pleased my build has grabbed your attention and that it has got you building a bit of iconic British armour. My build has stalled while I work out how to tackle the diorama, but it will return very soon.