MH 1.1.0 OSX Proxy files

I have downloaded some proxy files with extensions .proxy, .obj, and .thumb - I have placed them within the folder user/Documents/MakeHuman/v1/Data/proxymeshes with the consistent sub-folder name, but MH does not seem to pick them up at all. I have also tried putting them in the similar folder within the MH application package folder with the same result. I notice that the built-in proxies use file extensions .mhpxy, .npz & .thumb.
Where am I going wrong?
Where am I going wrong?