Thought I was correct regarding the Cemex HOA.
Slightly off topic, I'm having a go at converting an EWS HTA into a Tarmac HYA. This includes removing a section of the wagon, adjusting the slope of the end of the wagon, fitting LTF25 bogies, fitting buffers and hook and chain coupling, plus a couple of other alterations along the solebar.
Unfortunately no one has ever made a GBRF HYA or IIA coal wagon in OO to make an easy HYA / IIA aggregate wagon