Martin Kovac's channel Night Shift has some great weathering videos.
https://m.youtube.com/channel/UCNM5EknY1XBA9buLmJqYLdw
I'm giving weathering with oils a try, and found Abteilung 502/AK's book on the subject to be helpful (and cheaper on their website than eBay or Amazon, even with shipping).
https://ak-interactive.com/product/mastering-oils-1-oil-painting-techniques-on-afvs/