Which models should I use for image colourisation and enhancement

I am trying to create a gift for someone where I’ll enhance and colourise some old b + w photos from the 40s and 50s that are very meaningful to the person.

So far I’ve just used some generic tool on google where I upload the image and download the result (separate tools for upscaling and and colourization). The results were OK but I was wondering if anyone can point me in a direction for any diffusers/models to use on HF which might yield better results, not sure whether stable diffusion would be the best option for this goal or not. Long term I’ll aim to deploy this to SageMaker and upload a series of old photos.

Any help/advice would be greatly appreciated!

For reference, here’s an example of a before + after using generic drag and drop tools on google: