I could not find the answer for you, but I speculate not many: the frozen dna was only stored for 35 years. Cloning also does not need to introduce additional mutations into the dna afaik. So I'd expect very few if any mutations from the material they froze.

And to the reconstruction: I don't think it does in this case. As they talk about working with frozen cells and we are not in the realm of frozen Mammuts who's genomes has degraded and needs to be reconstructed. In that case yes, we would talk about smaller pieces.

Thanks, that's another fantastic answer.