Priitkasikov.
I have emailed the Coventry Transport Museum with links to your pictures.
I don't know enough to help you very much with your machine because it is obviously older than mine, but if the Museum can't help you I will be very surprised.

When I get my Swift Club membership sorted I will have some sort of access to all the other Swift owners.
And things should start moving then.
I would think/expect spares to be available within the community.
I know for sure that some Swift decals are available, for a price!

Does your have a head-badge?
Mine has a decal only.