I tried the Galactica, based on info from the shows and the online Tech Manual. It was quite hard. The size figure on the Tech Manual is the most accurate, as it's based on size comparisons with Vipers and Cylon Raiders (which we've seen next to people and can thus size accurately). That makes her about Size 11 or 12, but given the low power of her systems (laser weaponry, no faster than 0.25c at sublight, unknown FTL propulsion but speculated some sort of hyperdrive and no shields except perhaps very low power ones - Cain orders the Battlestar Pegasus to "put electromagnetic defence screens to full power") it's extremely hard to fill up that space with Spacedock SU costs. It's possible, but she's extremely weak compared to a Trek ship of similar size.
"That might have been the biggest mistake of my life..."
"It is unlikely. I predict there is scope for even greater mistakes in the future given your obvious talent for them."
Vila and Orac, Blake's Seven