Last month I managed to get 25 of these guys converted from a combination of the Mechanicus Vanguard and a selection of Chaos Cultists that I had.
These are now painted and have been used in game with great success, tying up those pesky marines with their 4+ carapace armour and 4+ feel no pain(Lacraemerta Tech Auxila adept).
I have been using them happily in game, better pics to follow.
Further on from this I also acknowledged the need for more Mech bodies so I've purchased 2 more Castellax and a trio of generic Thallax. They will get the same conversion work as the rest to make them just the right amount of tainted.
Next project is converting this lot.
Also, this will need a look in too, my Mortalis ship bridge started.
Stuff to follow next week! Lots to do!