Rodney

Those ones you posted are new to me. The last time I looked was several months ago and there was one or two people selling the bulbs for $30 each or so IIRC. One member made his own but had a separate 12V transformer to power it. I think he may have hid the transformer in the case.
The Singer machines take the bayonet mount bulbs but most Japanese machines I've seen take screw in types.
Rodney

Cari-in-Oly

The one you saw with the transformer might have been based on a Necchi. Some of them use 12V auto bulbs and use a transformer.

Cari

diamondee

Thank you Cari for the link. Thank you all for taking your time to read and post. I appreciate it and look forward to reading them all.