Hello, I have just joined the forum. My name is Deborah Bell and I run a mechanical watch and clock museum with my mother, in Haltwhistle Northumberland- 'Mr George's Museum of Time'. The museum is based around a series of children's stories which my mum wrote about her father who was a watch and clock repairer in Northumberland- the 'Mr George the clockman stories'. My mum became a repairer herself and has a huge collection of watches, clocks, tools and parts so we decided to bring everything together so children could learn all about mechanical "proper" time and Mr George, and adults could look at the collection and reminisce. She still repairs both watches and clocks now and has her workshop on our museum premises!
if you read the technical document found above you'll notice on page 3 there is reference to another document? This is the document you need which explains how to fix the problem of the new weight becoming stuck if it's not properly adjusted. The only problem is you're not going to have the tools. But in the absence of lacking of the proper tools I'm extracting out the text that you will find interesting
"The new oscillating weight becomes stuck if it is not adjusted to the stud (pin). The new studs designed for the oscillating weight in the calibre 550 family are 0.698 to 0.701 mm in diameter."
The reamer is described as "Hard metal precision reamer Diameter 0,702 mm Reference 516 0072" then even if you can find the reamer you need the spindle that holds it in the staking set. So what we get out of this is the axle is over size and you need to open the hole to 0,702 mm. I would suggest not using the old parts just replace both of them. then if you're careful you can use watchweasol instructions with a brooch which will work just be careful it's easy to go too far.