so, you decided to use one of my well researched drawings as base for your own drawing. nothing wrong with that, but you will run into some trouble with the way you modified her.
- you cut all the rigging designed to keep the masts from falling backwards. this will limit your ship to sailing only with the wind from astern, anything with wind from the sides or even worse, somewhat forward, will mean your masts go overboard.
- you made the rudder at least 2 times smaller, which means you can no longer hold course.
- the rudder is now only below the waterline, which means you will have to invent (they did not have this on any ship at the time) an watertight connection from your steering mechanism to your rudder, otherwise your ship will be sinking.
- you removed all anchor handling gear from the ship
- quite a few lines from the stern and keel now end somewhere halfway.
- you added a gun amidships which is half a deck higher then the guns were, and from the looks of it quite a bit heavier. this means you can carry less sail then the real ship, and carry less stores.
- you no longer have chasing guns
- your bowsprit is not actually secured.
- you removed the copper, but not actually coppered her hull?
- with the new stern shape, the hull shading is most likely no longer accurate.
- the last brig closely following this design was decommissioned 1849, and this particular ship was scrapped in 1822. I very much doubt this rigging would still be exactly like this on a ship build in 1858.
- The Irene actually carried 30 or 32 pounder carronades and 2 long 6 pounders. comparing that, 18 pounders seem quite heavy, even if you carry less of them.
I know very little of the vessels of this time, but the hull shape looks very wrong. in the first place, because you have a funnel amidships, underneath there should be a boiler. a boiler is a big tank filled with water, so it is large and heavy. behind that is the machinery, connected to the propeller. however, in your hull, there is very little volume aft of the funnel, as the skeg begins aft of the forward mast already. in addition, your bowsprit is not connected, the weight of the aft gun is not supported by any volume underneath it and I see no place at all for your officers to control the vessel.
a small note, the first vessel has an huge oversized whitespace around it, so huge in fact that your image host has decided to resize the image.
may I suggest taking a bit more time with the vessels? I spend more then a month of research and drawing on the Irene alone, you just spit out 3 modified ship drawings with background stories in one day. of course, drawing anew takes more time then modifying an existing drawing, but it is hardly fair to the original authors to bash some big guns on the deck and remove and redraw some bits and add your name on it