I did a graft following the suggestions from Grasa.
Basically, wait for small roots on the rootstock and have some bud swelling/leaf start on the scion. In my case the diameter of both was the same and it was easy to match them. I used the Parafilm as a tape. The union is still in the moss until the roots become larger.
Rootstock: Adriatic, scion: Marseilles White. 
I had a bad luck with MW this season, very slow to root  so I am trying to get something going here.

While checking the sphagnum moss for the rooting progress, I found this little guy. It is very thin but going strong! It was cup potted today.

They both look great.  I hope they do well for you.

Thanks! I will post the graft update when the leaves appear!

make sure to provide that humidity dome when potting them up..  the graft tends to dry up quick..it looks very good.  when planting, don't add too much water to the potting soil and once in the humidity dome, the little water you provide stays in it... they look great , Igor!

no baby duck? :/

Nichole, didnt you see it next to the pencil?. Look at that gorgeous neck !
And the wings, and even the little feet ! :)

Please see an update.
The graft really took off! It helped that the native shoot was a little bit behind and all the energy went into the graft.
The Marseilles White leaves look very clean, no FMV so far!

Just as a side note, it may help to root the rootstock a little first. In my another post, I grafted an LSU Purple before the roots came out and it is not as good as this one (although the graft was much smaller).

Nice neat looking graft union...good luck with the project.

I removed the disintegrating tape on the graft. I was surprised to see how well it healed. It is almost not possible to see the union!
That was a beginner’s luck for sure!



   

Wow, I checked again today and I can see a little figlet appearing!
I will let it grow, want to see how far it gets.

That is amazing! Nicely done.

Strong work!