Bricks for RMH. Help Suggestions please

I have found these local bricks pictures below and wish to know if they could be used for a mass heater set up

that are approx 10"x10"x 5"
other patterns about I think am looking for more as i search around
Also I have many complete/whole mud and straw bricks
and a lot from a collapsed old barn
trying to reuse anything I have or can find
I have may many natural stones in various sizes and shapes

thanks in advance for any help suggestions

Frank