CTK Precision is now making a buttstock rail for the LUTH-AR MBA-1 and MBA-2 stocks. The rail allows for the addition of pretty much anything compatible with a Picatinny mount. However, it is most likely intended to be used with a monopod like the Ultimate Rail-Pod.
The buttstock rail is CNC machined from 6061 aluminum and has a black hard coat anodized finish. It weighs about 0.7 ounces and is made in the United States.
According to CTK Precision, the rail mounts to the sling attachment point on the stock. Additionally, the rail has a sling mounting point so the owner does not lose a sling attachment point on the stock. The MSRP is $35.