That's right, they were bought out by an American company in the seventies...
There is a forum member here who works for them in the USA. I don't think US manufacture happened for a long time, however.
Proven Products had the sole Australian rights, but Topperformance started up as another importer in Melbourne about ten years after Proven began importing them.
Like many people here, I’ve had experiences with a variety of shock absorbers over the years.
For my classic Alfas, rebuilt Konis (yellows at the front and softer reds) at the back were pretty much the way to go. Firmer Bilsteins had a tendency to break the top body mounts.
I did have Spax on the front of my Alfetta and they were externally adjustable but not as durable as Konis.
My racing Alfetta has Konis rebuilt by Topperformance to a custom spec devised by one of Alfa race specialists. These have worked well in my car over a number of years and I believe a match for the Bilsteins. I did have access (for a while) to some trick double adjustable Koni steel tube shocks that were used by the Group C Alfas of the day. Rare and expensive, you need to access a race engineer to get the most out of them.
By Honda Integra has replacement Bilsteins that were put on a shock dyno at Heasmans in order to replicate that factory Showa units – as install the Bilsteins were way too firm at the front.
Proven Products is alive and well in Albury. They bought the Koni licence for motorcycle shock absorbers (Koni had stopped production in 2000) and makes these in Albury under their own Ikon brand and export shock absobers to the world. See http://www.ikonsuspe...ion_story.shtml.
A great Australian success story.