Hi Zephyr. I wholeheartedly support Your idea to start on SB with smaller ships, as I have the same approach.
Your drawing looks generally nice, but - despite being relative newbie here too, and not knowing much about that ship class - I have some thoughts about it.
(And forgive me any language issues - English is not my native language)
First of all - You should use SB-style railings (In the beginning I was drawing them - like You - "as they are in real life" - but older users insisted I draw them standard way - now it's my turn to insist that on You
) - two levels of bars with vertical bars 5 pixels apart.
I suppose that doors should be bit wider (one pixel perhaps) - I'm sometimes drawing more narrow doors to my ships, but that's because they wouldn't fit otherwise, and here You have lots of space.
Also, I think that there should be a light shade on hull just below the deck level, and the lower part of the bow should be made bit more rounded.
Not sure about that - but I'd rather make mast black, and gave a contour to the semi-circular thing on the stern.
Also, I would try to add more details.
And my last thought: on Your drawing and on the picture You've linked, the ship colour is beige-ish, but on
most pictures these ships look rather more grey.