The #5 is likely a manufacturing lot control number.Low cost guns of this period were made in small batches,[often out sourced]from components that were not completely interchangeable. Each gun in the batch was hand finished to acceptable standards and the control # was stamped on the key components so as to ensure to ensure that they stayed together through to completion of the gun.It is surprising that #5 is not evident on the action of the Grove.Perhaps when the action is stripped and cleaned you may discover a #5 stamped some where on the action. In the case of more expensive guns the serial # of the gun was used for lot control.
Lapogus; my Midland catalogue shows hammer guns with dolls head rib extensions and Greener cross bolts.The "Demon' gun shows a third bite in the dolls head. No sign of an ace of clubs/clover leaf rib extension![ In the past I have owned best guns of the same era that Clabrough made that used used the clover leaf rib extension]
