Techniques for emulating early color photography

[London]

I ran across an old color photography technique called photochrom and I'd love to figure out a way to emulate it. My first thought is to duplicate the image and make a monochrome version, then use a live procedural texture on the original to create a number of single, non-CMYK/RGB color overlays, but I'm not quite sure how to create the procedural texture to do that. Has anyone done something like this? Is there another approach I could experiment with?

[firstdefence]

Tough challenge, I found this: https://aircavs.wordpress.com/2010/06/18/photochrom-vintage-postcard/ doing a  google search, unfortunately the images are missing.

[appearsharmless]

Here's a screenshot of the entire webpage @firstdefence linked to, including images.

Photochrom Vintage Postcard.afphoto

[London]

Thank you, @firstdefence and @appearsharmless. That's exactly what I wanted and what my subpar searching skills weren't finding.

[firstdefence]

2 hours ago, London said:

Thank you, @firstdefence and @appearsharmless. That's exactly what I wanted and what my subpar searching skills weren't finding.

I think @appearsharmless used the wayback machine website, a very useful tool in these situations and one I’d forgotten about:
 https://web.archive.org/web/20141119055748/https://aircavs.wordpress.com/2010/06/18/photochrom-vintage-postcard/ 

[appearsharmless]

14 minutes ago, firstdefence said:

I think @appearsharmless used the wayback machine website, a very useful tool in these situations and one I’d forgotten about:
 https://web.archive.org/web/20141119055748/https://aircavs.wordpress.com/2010/06/18/photochrom-vintage-postcard/ 

Yup. And Firefox to take a screenshot of the entire webpage. And Affinity Photo to make an .afphoto file because I couldn't figure out how to attach a jpeg without it losing quality after the upload. 🤔