I've shot it at 25, 50, 100 and all the way up to 1600, and managed to get an image.
But with this test this time around, I decided to shoot it at 6ASA.
Was really impressed with the results. Although the highlights were a little hot, and I'm not sure if that's because of the meter on the A-1, shutter on the A1, or my developing. I'm going to lean more toward my developing, and over-cooking the film. I think that I should have developed it for 8:00 instead of 9:30.
Nonetheless, I am very impressed with the results, and can really see the advantages to shooting at such a low ASA speed.
HC-110 Dil. H (1+63) for 8:30 @ 20°C. The developing time I used was 9:30 but is slightly over-cooked, so I need to pull the time a bit lower.
Further testing will be required to lock in the exact timings, so I can aim to get repeated results.