Well, you made it look like cloth alright, but as a design choice...why is the roof made of cloth?
And hey, if you can't find any references, you can always make one yourself. Looks like you'd need, what, a box and some cloth and maybe a support to hold the cloth up? Household items, man. I rather like everything but the roof, myself. Your contrast, however needs some work. In some places the value jumps are too great, in others far too shallow. Well...maybe not too great, just right. It just looks wierd 'cause they're next to low-contrasted places.