I have a few covers, but none with an oil level sight. The cheapest is $22.50, including shipping. It is oxidized inside and out.
The best is $47.50 shipped. Inside is very good, with just a thin coating of gunk, light normal oxidation on outside, no scrapes, will easily polish up.
Have a couple more in-between priced.
None include oil pump, tach gear, oil screen or cover, or bolts. If you need them, they are extra. PM me if interested.