Just my two cents: I would try to keep the original parts. I did the kiwi-8p mod and kept everything. It’s more work but these parts are getting impossible to find. If you can preserve them you should. 

 

Hello,

A buyer of the Kiwi106 asked me whether he should remove the original
CPU by snipping of the legs and desolder the single legs, or whether he
should try to keep the original CPU complete and working. I find the
uPD7810/11 on ebay, so it should be easily replaceable. But according to
the datasheet the CPUs has an onboard ROM. Does this ROM contain parts
of the original firmware or is all firmware on the 2716 EPROM? Means:
can the CPU be replaced by any other uPD7810?

Regards
Florian

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http://www.florian-anwander.de