Hello
Thanks for the reply. I have not begin already to reassemble the bike, I waited for some advices about the play staying in the hinge, to don't have to disassemble it again if I had to weld the hinge pin. But I'll try it soon.
I thinked about put some Loctite on the screw, yes. For the test it will be some nail polish, rather equal as a soft loctite but cheaper.