Dean - sorry if this comes accross as obnoxious but thread resurrection is not going to magic the control arms into stock.
For the front lower and rear upper there are currently only 3 options that I know of as they are NLA at the factory
- Good used (not great option)
- Send them to Australia for them to inject the ball joint with resin- not an option if the ball joint has play in it
- Send them to a company in Slovenia who can apparently rebuild them. I don't know anyone who has tried it in the Maserati community but a YouTuber called Jayemmoncars sent his Lamborghini arms to them that are a similar design and they rebuilt them. https://www.vps-eu.com/shop
The front upper the arm has a replaceable ball joint
The rear lower is the same as options 1, 2 & 3 plus an option 4 which is that Eurospares manufacture/stock rear lower pattern arms.
Hopefully someone like Eurospares with the money and resources will step in to sort this out for the community like they have done with the lower rears. I doubt a private individual can get it off the ground unless they have a huge amount of cash to front it. I am trying to get a pattern gearknob engineered for the 4200GT and it's looking like at least £3500 worth of investment to get a small batch of samples made - would hate to think the costs of backwards engineering these control arms and then the indemnity insurance that comes with it (what if one snaps while you are driving at 100mph, who are you going to take to court?)
Oh I forgot to mention you never know Maserati might decide to start making parts for these old tipos but I think pigs are more likely to fly before that happens.