I think it would be about VF details but looks to have been cleaned at some time. I don't see any cud, a cud is a die break that involves the rim of the coin. A piece of the edge of a die breaks away, and any coins struck from that die will have a bulge at the rim where the metal flowed out into the void.
Don,
Thanks for the link on grading early classic silver coins. It makes sense to use the reverse as the primary side for grading if the obverse dies had weak devices and were not well struck.
The link pertained to dollars but the reverse on the half is used for grading as well?
BTW- Did you mean AU 55 for the grade on the OP's coin?
I missed it in the link if it said so, but the cleaning doesn't come into play and change the grade to "Details" on the OP's coin?