Finally got back to working on ayttm after a, well, work break ;)
I spent the last 3 hours fighting with gpgme-1.x and have finally managed to get some things working. The strangest problem (and it took me quite a while to catch hold of) was that the deprecated gpgme_data_rewind(foo) was working but its non-deprecated replacement gpgme_data_seek(foo, 0, SEEK_SET) wouldn't work at all, unlike what the gpgme info docs said. Copy+paste it from the info docs and it still wouldn't work. I'll update if I get it working.
Instead of GPGME API reference., I went for GPGME Reference and I found the GPGME API Reference Manual.