I am short a few Leman Russ tanks (inbound from Ebay) but work has started on the other Iron Cult vehicles. They are bashed together from whatever leftover imperial parts I had in my bitz box.
The first armoured artillery squadron are fairly straightforward Basilisks. I had to add some fuel tanks and Green Stuff items to the older models to “bulk” them to the new size (I only had two of the newer types left).
The second squadron uses spare Basilisk chassis but mounts siege mortars. I had those left over from the Ork Gargant kit and they somehow fit.
Finally I have two Hydra anti-air tanks. I have a bunch of Rhino hulls without tracks so I made wheels by cutting Ork plastic guns into two with a scroll saw. Add some Ork AA guns and an old Whirlwind launcher.
Once the weather is dry again these will get sprayed and then painted.