@clearthinker There are Technologies that have progressed and are in use today, due to their usage being proven to be fit for purpose. That have been cutting edge in providing non metal solutions for the methods employed to produce a mechanical device in all sectors of industry.
Aviation and Performance Vehicles are using Wood Products produced using very accurate and reliable methods for their construction, these wood products can be machined to have the tightest of tolerances, no different to a metal and will remain stable to perform as per their designed for function in all environments met.
The same Industries as above, are also using Composites and Thermoplastics, of which the merits for their usage is very well versed and adopted by numerous industries, each are known for their capability to be used in place of a metal.
The use of such materials are much more planet friendly as their production is not as energy absorbing as metals and the methods used to form shapes from the non metal materials, is requiring much less energy when moulding or machining.
Used as a Material Globally, the improvement in the environmental impact on the Planet, when selecting non metal materials is encouraged that is a good thing for all.
There are alternatives to the above, and methods can be adopted that will be the better for all.
All the above does not offer the same energy preservation as choosing to buy a already produced TT from a Vintage era, over a modern design.
Any methods where a obsolete Design/Model is given a resurrection and a second life gets my vote over any other methods used to acquire a device.
If the chosen model is seen to be a little needy in some areas, and the wish is to get the device back up to a Top Level of performance, then why not see if a Modern Method for using materials will be fitting for ones needs.
I am slowly going through the process of swapping out worn sacrificial Bearing Housing Parts for ones produced from Thermoplastics and other non metal materials.