In my opinion, your ability to obtain a Fender-like clean tone is highly dependent upon what speaker you're using.
I have a Mark IIC(+), a Triaxis/2:90, and a Fender 65 deluxe reverb reissue. I've taken all three amps and swapped them around to different speakers including the Jensen in the Deluxe Reverb, the EVM-12L in an open and closed cab, and a Celestion V30 in an open and closed cab.
Clearly, the closed cabs sound wrong if going for a Fender sound. Don't use a closed cab.
For the open cab sounds, only the Jensen sounded like a Fender. The Fender through the EVM sounded pretty good, but not like a Fender. Only the Jensen had that Fender mojo.
When I then played the Mark IIC+ through the Jensen, it sounded pretty good, but still not like a Fender either. The Fender was much looser sounded. There were some deep deep lows in the clean channel of the Fender that just weren't there in the Mark IIC. The Fender was also looser feeling...a little less conjested. Oh, and the reverb on the Deluxe Reverb was way more engaging (and had the potential to be way stronger) than on the Mark IIC.
Basically, think of instrumental surf-rock (dick dale) with its heavy use of clean-amp palm muting, fast fast thumpa-thumpa riffs, and super-wet drenched reverb. These are all the things that sound great on a fender and sound pretty uninspiring on the Mark.
Don't get me wrong, I play my Mark IIC (even clean) way more than the Fender. But the Mark IIC(+) is no Fender. It's a different sound. A big part of the difference is the speaker. Even with that said, though, there is still an inherent difference in the sound, too.
The Mark I is quite different and the Mark IIa and IIb are fairly different from the IIC+ and later Mark amps (III and IV, at least). So, those earlier amps might do a better job of getting (or even improving?) the Fender sound.
Chip