MC40a Light Cruiser:
(Computer modeled image:)
I like to imagine this ship more like 2 parts, than the one part sections the more modern images show. there is the forward top module, and the lower rear section that is "along for the ride" (Being pulled by the engines, of course firmly attached to the forward section, it just lacks a lot of the machinery and is where passengers are for cruises). I dunno, seems more interesting of a ship when viewed that way, less cigar shaped like the rest of the fleet.
ANYWAYS:
The Nebulon B is a 300 meter long vessel, and the Assault Frigate MrkII is 700 meters, and Wookieepedia says it is between 500-600 meters. Lets go 500, keeps a nice 200m jump between the classes.
Armament:
-14 Turbolasers
-18 Ion Cannons
-2 Bombardment Missile Launchers
Also equipped with a hanger that holds 1 squadron or 24 fighters (wtf make up your mind already wiki's)
You might notice the lack of any and all point defense guns, like laser cannons. That might just be an over-site of the TIE fighter game where the big ships weren't really supposed to shoot you down. Oops.
The standard battery for the rebel alliance seems to be 6 guns, so this ship has 3 ion batteries, and 2 turbolaser batteries, with 2 guns left over. That means 1 battery of ion cannons and turbolasers on each side (Port and Starboard) probably mounted on the back half of the ship, behind the front engines.
If I had to guess (and I do) on where 3rd Ion Cannon Battery went, it would be on the front of the ship at the prow. The remaining two turbolasers would either be their or in dorsal and ventral mounts singularly to at least provide coverage of those areas. Based on the "wings" it seems that the tip is a massive missile launcher, pointed forwards.
If you add it all up, you have 1 battery and the missiles facing the forward arc, 2 batteries on each of the side arcs, and maybe a blue or red die in the rear arc.
For Shields and Hull, it seems to be well endowed, and would be tanky and probably have a moncalamarian trait about migating critical hits because of redundancy systems and complex thick hull (MC30c would be the only exception)
Overall analysis is that this is a midrage ship with firepower less than the Assault Frigate but maybe greater resistance dispite the smaller size. God help it against TIE bombers though...