Attached is a coin I am about finished with. I have chosen the following description. But, what is called an A in the Mint Mark looks more like an H to me. Also, did I pick the correct symbol? Thanks for looking. Constans, AE follis, Siscia. DN CONSTA-NS PF AVG, pearl diademed, draped, cuirassed bust right. FEL TEMP-REPARATIO, Emperor standing left on galley, holding Phoenix on globe and labarum, piloted by Victory. Mintmark ASIS[SYM7]. RIC VIII Siscia 199 var (unlisted symbol). Dane's collection C781, March 2017.
Your workshop is A...H is not an option. During the production of this coin, there were five workshops open-- A,B, gamma, delta epsilon. You can compare the A in the mintmark with the A in the legends. The obverse is not so helpful, but compare the first A in REPARATIO, it is also open at the top. For the RIC number you need a size. It is hard to tell, but it looks like a small module (circa 18mm) versus the large module (circa 24mm)
In this case the coin has several A's other than the one in the mintmark and all have squared and open tops. We have to accept the fact that Romans did not learn to make letters in the way we learned in modern Kindergarten and that the several mints did not all agree on such matters either.