Yesterday the "hard to find" 21.477 MHz crystals arrived from Aliexpress :-)
Today I soldered the SDIP64 adapter PCB and tested the V9938 with the R65C02 @ 3.58 MHz (Yamaha cpuclock =1/6).
I connected the 32k SRAM with the latch - like at the 9129 - and it works!
I connected the composite out with an simple emitter follower to my Commodore 1084S.
You see - there's something wrong - it looks a little bit shaked ;-) - but I have a picture!
Tomorrow I will check the SRAM connections and test the circuit with a 16-bit DRAM.