All JAA FIs are restricted in accordance with JAR-FCL 1.325 (a). So until they have met the requirement and been recommended by a supervising FI who must be notified to the CAA if they are instructing in a UK RF they cannot act as anything else other than a FI(R).
The fact that other countries do not issue a specific Restricted FI Rating does not change the JAA requirement.
If there is an accident and it is proved that the requirement was not met then you will finish up uninsured and with a lot of liability!