It has to come off, the flash hider/Bull Barrel assembly won't seat all the way with it on.
The three most glaring problems I see and will fix first is the heat sink, the grips, and the black disk on the side opposite the scope. That should be a very thin silver disk right?
I'm no expert (consult the other threads here for that ), but I believe the silver disk was machined out of the body. My introduction to obsessing over the DL-44 was the Tested article and video, and I'm not yet at the point of wanting an accurate one myself - just good enough for trooping now.
Here's mine after about an hour with some sandpaper and steel wool. I feel I went a little overboard on the barrel of the flash hider - I got distracted a critical moment and had high contrast black/silver banding that didn't look good, so I had to take it down to a more uniform silver. The finish flips very very quickly from black to silver - takes a while to have any noticeable effect at all with #0000 steel wool, and then BAM! Down to bare metal in an instant.
View attachment 669124 View attachment 669123
Again, I'm not going for any kind of accurizing with the damage here, just an appropriate level of wear.
Todds costumes has the tomtit parts you need to make an accurate ANH grill, and they're cheap.