Yes,
Rejuvinator can be sprayed on the existing dope. It will make it look
like new.
Quite often ringworm can be fixed with rejuvinator and a finger,
carefully working the dope together.
i did it on an old tripacer I owned and worked like a charm.
On some of the ringworm repairs i had to spray a little color dope to
make it blend in better.

Good luck

Dave

Michael Horowitz wrote:
Am I correct that 'ringworming' is caused by the placticizers's having
evaporated form a dope finish, and the condition can be corrected by
re-introducing placticizers via a 'rejuvinator' ?- Mike