I think it looks pretty good for a first attempt.
This is where I find scratchbuilding fun, look through your parts stash for a bit of photo etch that looks like the floor grating.
Radars, flight deck netting etc, cut to fit and glue it on top of the new floor piece. But make the floor piece out of plain flat sheet.
A couple of suggestions,
First, Attach a new floor piece to the main section. Make it a little longer side to side, so that the sides stick out. Make sure to align it vertically so that any PE grate you put on will sit flush with existing floor grate.
Now attach what you have found for the floor grate, making sure to align it to the existing grate and that is sits flush with the existing grate.
Next, attach the new side block extensions, ensure they follow the same angle as the existing pieces. leave a bit extra extending fwd over the new deck piece.
Then, sand/cut/file flush across the whole front end. Do the same with the cut edge of the piece you cut off. Sand/trim until the cut piece sits flush with the new extension pieces.
Next, glue the front piece back on to the new extension.
When dry, sand the sides and top smooth and fill any remaining imperfections with putty and sand smooth again.

I think it looks pretty good for a first attempt.
This is where I find scratchbuilding fun, look through your parts stash for a bit of photo etch that looks like the floor grating.
Radars, flight deck netting etc, cut to fit and glue it on top of the new floor piece. But make the floor piece out of plain flat sheet.
A couple of suggestions,
First, Attach a new floor piece to the main section. Make it a little longer side to side, so that the sides stick out. Make sure to align it vertically so that any PE grate you put on will sit flush with existing floor grate.
[img]http://www.resinshipyard.com/pictures/Ark%20Model%20mod%201.jpg[/img]
Now attach what you have found for the floor grate, making sure to align it to the existing grate and that is sits flush with the existing grate.
Next, attach the new side block extensions, ensure they follow the same angle as the existing pieces. leave a bit extra extending fwd over the new deck piece.
[img]http://www.resinshipyard.com/pictures/Ark%20Model%20mod%202.jpg[/img]
Then, sand/cut/file flush across the whole front end. Do the same with the cut edge of the piece you cut off. Sand/trim until the cut piece sits flush with the new extension pieces.
[img]http://www.resinshipyard.com/pictures/Ark%20Model%20mod%203.jpg[/img]
Next, glue the front piece back on to the new extension.
When dry, sand the sides and top smooth and fill any remaining imperfections with putty and sand smooth again.
[img]http://www.resinshipyard.com/pictures/Ark%20Model%20mod%204.jpg[/img]