At the moment he is going through a molt yes, so I think his fur will be looking lots and lots better in a few weeks from now.
He has not gained (or lost) any weight since he's been neutered, but the last year I changed a lot in his diet. (I had two rabbit, Fred (2004) and Indy (2003), about a year and half ago, Indy started to get all kinds of problems, with his teeth, he had EC, with his bowel and calcium related urinary problems.. Turned out their diet wasn't really healthy.. Unfortunately Indy died last february. Maybe now you understand my concerns, Indy was about the same age as Fred is now when all the troubles started..)
I'm not English and I have no clue what you call it, but I used to feed them the stuff that's in Joy's bowl on
this picture (as you can see, Joy was suffering from EC, he died in October 2008..) so too much fat, too much proteins, too much calcium.. Too much of everything..
But when Indy got sick, february 2009, I started feeding them SS, and more veggies, Indy refused to eat hay, Fred barely ate it either so I worked on that as well.. It took me months to sort all that out and I think he has a very healthy diet now, but you can understand his weight has been unstable for quite some time. He weighed 1600 grams last december, and now he's around 1500/1550.
The only thing changed in the past six months is him getting neutered and him getting a girlfriend.. He has been living outside his whole life. Although, his hutch is twice as big as it used to be.. And because I don't have to switch (I couldn't let him and Indy at the same time), he can walk around the garden twice as long.. But all this already changed when Indy got sick (november).