I believe that the Stampe will be migrated to the Permit system by the CAA because there is no longer anyone supporting the type. Therefore you will not have any choice in the matter, but I would imagine that few people will worry about that given what I understand to be the huge cost of maintaining the airframe on a C of A. It is difficult to see the disadvantage of this move for Stampe owners, who might otherwise have faced a bleak future.
The Christen Eagle in which I have a share is being recovered in Stik's hangar at the moment. I hate to think what that would cost in a licensed maintenance organisation. I believe recovering a Pitts if it is on a C of A can cost around £20k
.
I know that a few years ago a few makes and models had the option of either being on a C of A or moving to a Permit, but the CAA put a stop to the practice, on the basis that types which were fully supported should remain on a C of A and not be able to duck out of the regulatory regime where there was no justification (the huge cost of maintaining an aircraft on a C of A was not considered to be justification
).