Sorry for the late response. I have been trying to track down spare parts. I believe I've figured out what marker this is. I think it's a Kingman Spyder Compact P by the looks of this diagram.
Today I added a striker spring guide (27) and a Flat disc (27A) to the marker as well as one of the special red striker o-rings and it still burps and will not recock. I've played with the velocity adjuster again and it still won't work. I've swapped the valve spring and main springs with other stock springs and nothing. Anybody have any other ideas?