According to the Marantz DV 4300 codes on the Marantz website, Kam is correct. It is RC6 and his codes are correct:

On
6000 0000 0000 0001 0029 00c9
Off
6000 0000 0000 0001 0029 00ca

Also, the decoding your toggle for the Mitsubishi VCR would indicate that Kam's discrete On and Off codes are correct. (same device code)

In decoding what you remote changed on those VCR codes they are trivial differences and should work.

In decoding your DVD power toggle, there must be some characters missing because it does not seem to match the website or RC6 unless I made a logic error. Could you repost that.

You can buy a One-For-All remote and buy or build a JP1 cable for between ~$30 to ~$50 total and it can do both of those commands. It may be that the Mitsubishi VCR does not respond to discrete commands.

Did you try the Play command from Off?

-Jon