some updates...

the Radio Flyer project got a little progress, the cart tyres are finally mounted on the rims:

complete with new valves. The guys from Daytona Indoor cart in Essen http://www.daytonakartbahn.de/Home.aspx were super nice and helped me out with their equipment and knowledge- Thanks for that!
...  this is how the rims looked before:

For my new motor I bought another set of cylinder heads - 044 series, already machined for 92/94mm pistons:

and I found another engine case, with 8mm studs instead of 10mm studs - which allows ~ 2,1 liter displacement :-)

The Volksback itself is now equipped with the classic style Radio - and some good working speakers:

The chrome style fits really well with all the other chrome levers in the dashboard! Even the integrated Bluetooth hands free function works perfect! ( unless the motor gets too loud...)

I used some MDF board and mounted 2 speakers in the original speaker position:

The Emphaser ECX80 S4 speakers have big magnets for their overall size - it is still no High Fidelity, but it works o.k. for me and I didn't had to butcher up any visible Interior to make them fit!