Praetorian Lascannon Conversion

I have started painting some of the models I recently put together and while the original Praetorians are coming on slowly, the Penals have ground to a halt while I wait for a pot of Adeptus Battlegrey. Thats so I can paint their overalls in the style of Gandalf's cloak found here. So I thought I would show what I will be using in the batteries (Heavy Weapon Squads) and as  heavy guns in my veteran squads, either Lascannons as shown or Autocannons.  I liked the conversions using ork wheels but they just weren't Praetorian enough for me. So I came up with this very simple conversion. I really like this, the simplicity without the front panel really helps it look like an old artillery piece to me. I like the wheels but I'm not sure if maybe the wheel rim would look better thicker? That was my gut feeling but seeing it photographed I think the current wheels look really good. Would welcome others thoughts.