Received the parts! I guess Zacconi Workshop sent the items before I paid them

Costs:
Dispersion screen (part 59)......EUR 6,70
Portafilter Gasket (part 55?).....EUR 2,90
Group-to-Boiler, seal (part 50)..EUR 3,20
Piston seals (2x) (part 57).......EUR 2,90+2,90
Payment via PayPal, Zacconi Workshop (Tomaso) is very quick, clear in their emails, nice to order from!
By the way, I asked espressomaschinendoctor.de whether they had the dispersion screen, they didnt, but now I see it posted. espressomaschinendoctor.de is quite a bit more expensive though. (i.e. Portafilter Gasket -O-ring- 2,90 EUR vs 6.50 EUR).
I'm in the middle of moving to another appartment, so not sure if I'll have the time now to fix it, coming month maybe. I'll keep you posted and continue posting photo's and updates for future readers and questions.