That was quick !
At least one of those wheels looks a bit bantam-ish ?
Always a good source of common stuff.
How fixed do you want them to get. ?
Generally, the last thing you want to do with a long term project is to buy new tyres early on.
If you do it now, by the time the rest of it is done, they may be (well past) their use by date.
If they still pump up, you can use them to move it about the workshop, as is ?.
If you have forks and suspension bits ...
At least we know you are in Oz, so someone local may be able to assist.
I've always just accepted that the early history may be long gone and irretrievable,
but you never know. Good luck.