Yes i get that Vincent my suspicious mind just makes me question how the dust got in , i use K&N filters and i've had it "dusted" until i could feel it effecting performance but it was clean inside , and i imagine any dust that did get into oil would congeal sink to the bottom of the sump and stay there until oil change ?
I'm inclined to think the seller failed to mention a specific event such as a post filter split in the intake or some such thing that on discovery prompted the need for a quick sale . But i guess we will never know and bravo for saving the truck
On a side note would you consider adopting a 45 year old male from the UK i'm almost house trained and i have 3 trucks that could all do with some TLC