Apologies that I have no progress shots, but here's a quick and easy conversion I did to turn a dread I had lying around into an Ironclad with a Seismic hammer for a real small salamanders army i've been putting together
parts:
plastic (or metal i guess) lascannon dreadnought arm
flat disc thing from a rhino chasis model (the ones used to fill in the hatch opening holes... i don't know what the part is called)
step one, snip off the end of the lascannon arm, leaving the rest of the barrel in place. file the end until it's flat, so as to make a nice connection.
step two, glue the disc thing in place.
the barrels give the arm a nice hydraulic hammer look.
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