I`m looking for a tang mounted peep sight for a 1899 savage that a friend of mine purchased in 250-3000 cal. and he wants to restore to original as possible. I`m hoping someone here may have one or be able to tell me places to look, any help would be appreciated.

Theres a Marbles on Gunbroker.

Ebay also. There seems to be more 99 tang sights than any other.
Example:

Lyman tang