Restauratie en identificatie van een transportfiets in Berlijn

Thanks a lot for the great archive and coverage about the long-lasting and very interesting history of the Dutch transportation bikes! I I hope it’s okay that I’m writing to you in English and I hope you’re healthy and fit in these times.

Due to the current Corona curfew and lockdown in the city of Berlin where I’m located, I’ve started to renovate my old transportation bike which I bought in 2014 in Terschuur and had wanted to renovate for a long time as it has gotten quite rusty and the front fork is loose.

I have four questions for you at this stage of the renovation:

1) I could actually locate the silver logo of the GWH label. GWH is only a logo of the spare parts producer, correct? Does the frame number 1 46119 tell you anything about the history or age of the bike? 
2) Do you also know how to open the bell? It seems like it comes with almost no screws but some sort of riveting. It’s so rusty but I would want to use it again.
3) And what about the headset of the front fork and the front fork itself? Do you possibly have photos of how they are constructed inside? I’m afraid of destroying it while opening it.
4) I consider to get the bike powder coated after having given it a treatment with glass bead blasting. Is there something to consider in terms of the material that makes those kinds of bikes different form other bikes and bike frames? The brass „smeernippel“ down by the bottom bracket (which seems to be made of copper? it seems so copper colored?) will need to be covered in any case. And is the kind of black a special black in terms of RAL or NCS color code standards?
Once I have the chance to take a look at the inside of the fork, I will have to order a few new spare parts (chain, rear hub, rear mudguard etc.) through Toon Mensinck via Nostalgie Oirschot, I guess. 

And a couple more photos featuring the achternaaf of the bike. It seems like it’s a torpedo one, yet I couldn’t locate a particular year. Also, something is written as “RM France” and I think it’s all different compartment mixed from different years.

Thanks in advance for your help and stay healthy!