I picked up a lot of Manuals the other day and found a gold-mine
of older tube scope manuals. They range from the 502 to the 541
and most all in-between. Let me know if you want to see the list.
They can be sent USPS Priority Mail, and are priced at $15 each,
shipped CONUS.
No Manual Merchants need apply.

73, Dick, W1KSZ