Have you seen this one? Ive just downloaded it from these forums and its the only current free one I can find (Dec 19) Editing is a bit tricky at first, just play around with each layer individually and you should be able to come up with some ideas/techniques. This is my very first attempt using it without any fine tuning to give you an idea..
(Where do you guys host pics? Seems all I can do is just post the links to images?) - CELTICS CITY REDESIGN - https://ibb.co/gJrZZ2t
And heres the link to the mockup: