Datel titles usually have their main code starting at 0x50000000. If that area is completely blank, your dump is probably bad. Cleanrip 2.1.1 doesn't know what to do with most datel titles and will have everything after 0x01F00000 zero'd out without trying to read it, while 2.0.0-datel2 will attempt to read it, ignoring any errors for the unreadable sectors and filling those sectors with 0x55. If everything is still 0x55, that's a bad sign. Also if there are 0x55-filled sectors in the middle of code that otherwise looks fine, that's probably a bad sign.
Check if the game starts properly on console; if it's unable to read it normally when you launch it, then there's no hope of cleanrip doing the right thing unfortunately. Otherwise, you can try testing your dumps with dolphin; Datel being Datel the games don't launch unless you've got the GC bios and have DSP LLE enabled though. If you get error messages other than FIFO overruns, and if it doesn't start, your dump probably still isn't correct.
Even if you eventually get something that matches what's in the database, verification dumps are always useful (especially for discs as volatile as these).
It's also worth noting that the numbers in the ringcode can be the same for multiple discs; Advance Game Port and both Cheat Construction Kit videos (PAL and NTSC) are 04070501 (see images), though they have different text. To my understanding, the numbers are a date (in the form of year month day 01); the Cube magazine discs help establish this.
My dump has data at 0x50000000 which ends at 0x50300000, something the verified dump doesn't have. My dump boots on a wii via nintendont and on dolphin with the settings you described. I couldn't do that with the verified dump. Using a hex editor, I found that the verified dump is missing a lot of data that my dump seems to have. Using a hex editor, I found the verified dump is missing lots of random chunks of data. I tried mapping it out all the differences between my dump and the verified dump, but gave up after the 8th missing chunk of data that I found.
I used cleanrip 2.1.1 with these skip settings.
<skipcrc crc100000="50CD767F" skipfill="55"/>
<skip start="01F00000" stop="4FFFFFFF"/>
<skip start="50300000" stop="570FFFFF"/>And I consistently get a working dump with the same hash. I am currently dumping it again with 2.0.0-datel2, but I really hate how long it takes, especially knowing these disks are prone to failure. My disk is in pretty amazing condition. Once it is done I'll compare the ring codes and see if there's any differences.
If anyone would like my dumped file for investigation, I would be happy to supply it via PM or something.