I did find this one:
Ferplast 84646099 Wood Home for Rabbits, Without 4646, 33 x 23.6 x 16 cm
https://www.amazon.co.uk/dp/B001MZUY...48F928NN?psc=1
But the 33cm is £20. The small one is £11 but for less price I could make one out of popsicle sticks and have it exactly how I want. Just worry about the waterproof of it and how easy it is to clean. The size of the smaller one is about 3cm larger than my original one I made as well so it’s not much in it.
I’ll look up plastikote, is it safe for hamsters if they did chew it? Or one of those things where you’d need to remove it if they started to chew?