Remington 12A cartridge retainer

[jvik]

Can any provide a picture of how the cartridge retainer is assembled in the 12A? This is a pre 620,000 whatever serial number rifle. It came to me missing the retainer. I purchased one from Wisner's, the part looks like I remember it (this is an old family gun) but for the life of me I cannot remember how it goes together.

Thanks!