Well, they'd have to move on to plutonium production, which is a whole 'nother level.
Be easier for the russians to just sell them one.
Yes, that is what I am afraid of. Unless they bought the plutonium from someone, it will hopefully take them sometime before they can begin production, but foreign assistance could allow them to begin production relatively quickly. But it would be easier for Iran to acquire Russian weapons, which is a definite possibility. Russian weapons appear in Iran's hands all they time. The ease at which they can acquire the most advanced Russian and Chinese weapons is astounding.