Thanks for the photo, looks very nice indeed.
The fore end weight was a feature of the initial FWB rifle, the model 150. Have never seen one on a 300 but don't know why it wouldn't fit. The 300 and 300S typically have a barrel sleeve weight instead.
The things hanging under the fore end rail are of course not FWB OEM pieces. It's a total gas to shoot one of these old rifles with the big free-rifle palm rest though, I have a couple of them that I love to play with.
Do NOT let them ship the gun in that case, unless they add further bracing and remove the sight so it can be separately wrapped. The gun WILL move if the case is banged hard or dropped and damage can result (and yes, I learned this one the hard way).