, I am lucky to know the owner of a stainless steel fabrication company. I was an apprentice with him over 35 years ago, so I just pop in and raid his offcuts bin.
I made the missing weights out of a stack of 5 or 6 halfpennies with a copper rivet through the middle. They work out at just about the same size and weight as the originals. I used halfpennies because I have 100s of them and no halfpenny machines
As for the case, I managed to rescue the original back and the original front door, the rest I made from 18mm MDF, and finished it with a paint splatter finish and a clear top coat Why MDF?..... because I had lots of it at the time. I also added my own top flash just to finish it off.
And as raj was saying, you could try the local tip, sorry "Recycle Center", where I have been scrounging for the last 40 years, but since the Spaniards took over last year, they have made it a hanging offense to remove anything from the site, which kind of goes against there prime directive of Recycling???