Well, it turns out that the 15mm in and exhaust valves are too small to get me some more RPM's.
So need to get my hands on a Motom head with larger valves.
Luckily, one pops up on EBAY.
Ordered it and got it here with me.
First of all I let it glass blasted, to give it a nice clean look.
A nice useable set.
Ordered new valves, this time:
1) A 16mm Exhaust valve (original 15, but a 16 seems to fit)
2) A 17mm Inlet valve
Grind the valves in.
Machined about 0,2mm from the head in order to get them equally.
Extra rings to generate a more spring rate.
Shortened the M6 gear nut.
This will give me some space.
It is giving me the desired look.
Typical 50's, small cylinder with a large head.
But sadly these pictures were only taken for, the looks.
I need to get myself the correct valve key. As the one I have are not good enough. The 5mm valve key is different than the 4,5mm valve key.
Need to find them