Hi, I am looking for information on instructional grenades coming out of Bulgaria. There are RGD-5s, RGO-78s, and RG-42s all with very similar paint and markings. I am particularly interested in an RGD-5 I recently acquired. Its in near mint condition, so Id assume its an unissued factory made instructional grenade. However, where the paint has chipped away you can see a lighter green colour and there is evidence of stenciling under the outer paint (you can see a 78 to the right of the 5). If you have any knowledge of these grenades Id appreciate your comments. Thanks Colin