well, in fact many of the fs 1 era ships were still in use in fs 2, just in a lesser capacity, bc they were just that: old, outdated and underpowered, but still useful in some situations or extreme situations. I'd the most sorting out happened with fighters and here this mod should have no problems, since there is - naturally - a huge selection to pick from.
on the colossus: well, keep in minds they were speaking volume, and the colossus is a very compact vessel. you see, it is only about 3 times as long as an orion, so, while definately bigger, it's not worlds apart. weapons-wise of course you cannot match the original pattern, but sins (entrenchment) does allow up to three different weapons systems with different values in the four main directions and different target caps. therefore, you should be able to have 4 big beam weapons on board, starboard sides as well as one or two front and back. in addition you could add two out of the anti fighter lasers, normal and heavy turrents, flaks, missile launchers, etc. again with the same diverse configurations. it's not perfect, but it does allow for some possibilities. have no idea though what it would look like, maybe the 'banks' are automatically a more or less single point and you can scatter them around a bit. would be a pity.