I am positive that spider is not joshua. Especially if it is several molts out in your care. I think your spider is more along the lines of aphonopelma sp. 'hualapai' or what they call the 'eastern' mojave complex.... I really hate this whole taxonomy mess with these guys. I dont know what to call anything anymore. Joshua molts out with a smoky gray carapace and is a more lanky spider. Look at the foot pads of the last pair of legs or if you can, take a picture and post them and we will see if it's scopulae are divided.
Good morning Josh r, I appreciate your concern. If I don't have the Aphonopelma specie I posted, I would like to know what Aphonopelma species I have. I am very much interested in the dwarf specie. I found a older picture of, I believe, the same questionable A. joshua. What do you think?