Spa Headrest Pillows Replacements

Looking for spa headrest pillows for your spa, hot tub, swimspa?
You've probably noticed they're really hard to source. Here's why:

The same company made around 90% of the headrests for all spas in Australia. This include

Over time, the moulds were getting worn, labour costs increased, and the materials used are quite nasty during production.

One of the other big issues is that were hundreds of variations for each mould. Each spa manufacturer wanted their own lug-style, colour variations, etc... this was intentions.

Another issue: They need alot of space to manufacture

Many companies have looked at buying up the moulds, including us, but the costs vs sales benefits just aren't there. It's pretty unlikely anyone will pick them up.
What can I use to replace them?