Thank you guys for the info. I contacted a fellow member regarding the seatpost, I'll post more info once it's done
Here are some progress pics!
Making the in-frame tankless plate. Cardboard cutout.
I'm using this old under engine panel from an old cracked piece. The piece came from the top part of the shield.
Here's the final product, although I'm not sure on the color. Also don't mind the forks, those will not go on the bike. I have ordered some springer forks. I painted the plate a gold metallic color and shaved it a bit more to fit flush.
I'll make sure to get some better pics. I think for now the frame plate will do the overall design justice, so the gas tank will not be needed anytime soon
Thanks for all the help!!!