Thank You all!
I realy love the enthusiasm and positivity here, it realy does give a lot of motivation to de dust old hobby projects and realise childhood dreams!
Yes, í will also try some copper tape.
I a massive bag with those pipe toys just arrived from China, i think they will do great for larger pipes, i concider using small round nail heads for rivets.
(However, as a fun piece of history cast iron pipework where very seldom riveted in reality it was almost only industrial sheetmetal works that had those classic style rivets, i actualy found a piece of genuine antique drainpipe in a barn on my fathers farm whan i was a kid. It was way beyon rescue, but still interesting to see how it was made (yes, that's what i did whan i newer got any videogames from my parents... ha ha To be honest, i think kids toys are often unnessesary expensive and just one way to play with them today, not much room for your own imagination and to actualy be constructive, i think cognitive toys are very important for kids to hawe, whatever it id just pinecones with sticks as i had or expensive LEGO sets (wich me and my brother somtime got once a year if one had behaved well before Christmas, and of course my first model train set from grandpa, i must say that i realy was deeply impressed it still was in such a good condition it could so easily be repaired back to functional state when i found it in my parents attic and handeled it ower to my brothers children.

).).)
I will take pictures whan i hawe painted the parts, but at the moment it is difficult to reach the cities where i live bacause of well, reasons... But i hope it will lift soon.