BoomBoom, that's an awesome idea...I tend to make my own stands/gyms and even cages, etc., both from PVC and from Driftwood, Grapevine, Manzanita, Javawood, Pearwood, etc., a lot of which I just go out into the woods and at local vineyards and collect for free....however, I've got a question for you though....
I've never actually purchased an already-made, wooden parrot stand, like the ones you have. I have always actually gone outside on hikes in the woods and near lakes/streams and looked for large, multi-branched tree branches that look like they'll make a good stand, take them home, and then saw-off little branches/branches in the way, shaped them, shaved the bark off, and then attached the bottom to a wooden base using nails or wood screws and an electric drill..
My question is, "How are the horizontal branches on those stands attached to the vertical branches?" I have never seen one of these up-close (no bird shops or pet shops that sell these local to me or that I've ever seen before, surprisingly), and I can't tell just from photos that I've tried to look closely at what they are using to attach those horizontal branches with, as they look like they are just "laying" across and resting on the vertical branches, you can't see any fittings or anything. I once was going to try doing this by using a strong epoxy, but that wouldn't be "bird-safe" unless I was extremely careful to not drip any extra anywhere...I can't imagine nailing them or screwing them in, as they're too small to do so...And I once did it by using natural hemp twine and tying them, which worked great until the birds chewed the twine and the horizontal perches fell...I'm assuming they're glued somehow because you can't see any other signs of them being attached, but it would have to be a really strong glue/epoxy to hold them and support the weight of the birds, which I have, but I worry about using it...