The figures themselves are just the regular Cadian Heavy Weapons Squad, though honestly you get enough bits in that box to make up multiple squads if you're not picky about finding legs, arms, and torsos for the crew. I'm adding the Genestealer Cults Upgrade Frame for the heads and gear and using the Sector Imperialis bases.
Given the mortars don't take up a lot of real estate on the base, I decided to go with something new this time around. I've used a few of the plastic sandbags that come with the normal heavy weapon kit, but I waned to go a bit bigger this time. I'd picked up a couple of solutions including a mold to cast resin sandbags (which I'm still working on) and some flexible sand bags from Green Stuff World. I decided to give the flexible bags a try. You simply cut down the ends a bit, dip them in a mix of water and PVA (Elmer's) glue, and lay out your pattern. I tried a few different patterns to get the feel of what would and wouldn't work with them, and I'm pretty happy with the result.
The sand bags did take a couple of days to dry which is really the only drawback I've encountered so far. I hit them initially with some Agrax Earthshade, and then progressively highlighted them using several tan and yellow-tan Vallejo colors until I got the effect I was looking for. I then went back and hit them with another light wash of Earthshade. I purchased a pack of 50 of these, and have used roughly half of them on these three bases. Given how well they worked, I'll likely pick up more for future projects.
As with all of my larger scenic bases, I added some barbed wire to provide a little more visual interest. I also created a concrete section with AK Interactive Concrete and Ammo of Mig washes. The dirt and mud section on one of the bases also used Ammo of Mig ground cover and a couple of washes. I then just added a couple of tufts of static grass to complete the look. Overall I think these guys are ready to go. They're nothing spectacular on the table, but having an indirect fire weapon is always a good thing - especially early in a game!