You could do this, but you would have to mill off the rear of the cylinder to accomodate the thickness of the moonclip and the cartridge head. I don't know what the availablity of six shot .357 moonclips is, but I would think they are not common. Just my .02cents worth
I tend to agree with Dfariswheel. .45 ACP revolvers tend to work well with the moon clips in that the clip is relatively thick and rigid and the cartridge short and fat which facilitates the rounds dropping readily into the cylinder. On the .357s the clips are thinner and don't hold the rounds as rigidly and the cartridge is relatively long and narrow reducing the speed of reloading. There are, however, some .38 rounds that are relatively short which would overcome this objection to some degree but they are very low powered and obsolescent.
And then there is the change in value of the Python. Downward, I'm sure. It must be rather valuable in Israel as it is, without the cutting on the cylinder. What will it be worth after it is changed? Not as much as it is now, I would say.