I think the Portumac lid is a great quality helmet - but to me, it has too much of an Original Trilogy look to really hit the mark as a ROTS helmet.
The other helmet that someone posted pics of looks like one I have seen on eBay from a fellow in Australia. It looks very much like it is a re-cast of an MR helmet. So - I would expect that it would need a lot of work to make it troop-able (padding, straps to secure the face mask, mesh for the grille, nice tusks, better lenses, review and improvement of the dome attachment). But, concerns about re-casting aside for the moment, it may be possible to get it ready for a total investment that is a lot less than buying an MR lid.
I won't comment on the recasting issue. Opinions on that are well known and I think as adults, we can all make an informed decision on whether or not its appropriate to buy this product.
Huzz