Things to add, decoratively?
Hmm,
Honestly, I think you'd gotten most of the things I'd have suggested first, so great job!
But I can think of a few, ...
Literal logs strapped to the sides.
I'm aware they were used as armor, and if you don't want to do them because of that then that's fine.
Vision-blocks/ports
just the vision-port, like what is most often seen ringing/encircling the commnder's cupola, the driver's viewport in the forward upper glacis, or on the end of tank binoculars
A loop of cable
like, for a winch, probably with a hook/clamp on one of it's ends.
A Winch.
yes, this is only here thanks to the bit about cable reminding me that winchs exist.
Spare tread section.
yes, I know, Terratech went to a bit of effort to explain that all their "tracked" whels aren't linked-plate track, but instead treadmill belts. I don't care, WWII tanks carried spare track sections, so it should be there as a decoration
Rolls or loops of barbed wire.
literally like what was used, and is often still used, as infantry deterrent.
(and can commonly be seen atop prison fencing, to deter convicts from climbing.)
rolls being the wire still on the great big wheel is was shipped in, and loops being a bit more, deployed.
(like when it is in-use as an infantry deterrent)
