On a 23 year old young man of average height and build:

Classic Levi 501 jeans, in blue, white T-shirt and brown leather chelsea boots, with a brown leather sheepskin-lined flying jacket (like a WW2 bomber pilot).

Do you think this is an OK look?
I know it's summer but it's a bit chilly where I am! I'd just wear it out and about during the day.

yeah well sexy!!

well sounds fine but you should post a photo for better results. you can upload it free on http://Restyleme.com

Yes, very classic look, it's ok look

The jacket might be a bit much, would be OK in winter I would think but you would look a bit odd in the summer IMO.

well dont you sound like a snappy dresser! i bet it looks good, and if the weather near you is chillier than wherever we are- wear what keeps you warm and i really think that its a great look for a 23 year old guy.

Sounds fine, smart/casual

Where do you plan on wearing it?