A press tool is the obvious way, but I suspect very expensive. What you could investigate is getting them laser cut in the flat and then bending them to shape

The Blue colour is characteristic of spring steel, not mild steel, and the shape is vaguely familiar.

I doubt the maker would have specified special clips if anything standard off the shelf was available.  Trouble is there are gazillions of clips!  You could try wading through the RS Catalogue, or Magrenko’s online shop.  Magrenko also do bespoke work.  (Other suppliers available.)

Dave

If you Google classic car clips you will see many many many similarish spring clips pop up from various suppliers to the classic car restoration trade etc. There is a pretty good chance your piano maker used an existing clip from the auto trade, by far the world’s biggest consumer of such items.

Up to you to trawl through them all and find something that looks like your needs though!

Or try sending pics of your old clips to some classic car restoration experts or suppliers and ask if they recognise them.

Rippen pianos are still in business in the Netherlands. Would it be possible that they still use this type of clip?

Highly unlikely to be a standard part. There are lots of them and cheap to make apart from tooling. Manufacturers don’t price these things the same as hobbists.
It is a simple shape and if steel strip of the correct width can be found a very simple press tool would make the two locking tabs and cut it to length. Gauge plate die and a couple of punch pins ground from an old minimill would be good enough for a 100 off. A small rack press would be ideal but at a pinch you could use a vice.

Robert.

Michael not sure if you have seen this archive footage from TV https://www.rte.ie/archives/2021/0112/1189165-rippen-piano-factory/

I also found this

“The production of the Lindner piano began with founding a factory at
Shannon, Ireland. Only the plastic parts were produced at Shannon; the
normal parts were purchased from external suppliers, and Renner even
developed a special mechanism. The main factory at Ede in the
Netherlands supplied some parts as well.”

It might be worth enquiring from engineering companies around Shannon, although, as the factory closed in early 70’s the chances are slim of finding anyone who remembers making the clips.

On 18 August 2024 at 14:51 duncan webster 1 Said:

You can make a spring out of mild steel, just not a very good one. As long as you stay below the fatigue limit and/or elastic limit depending on application you can use any material you want […]

In the grand scheme of things, Duncan makes an important point

It is well-illustrated by the Flexure in the ‘Repeat-O-Meter’ device that was discussed recently. … the check-straps being essential to to prevent it failing.

MichaelG.