Toroid core numbers are Amidon designation. 10m filter 50db rejection of other bands. Other nice thing I have found. They have a very high input impedance outside of their passband. This makes them useful for splitting Beverage antennas between multiple receivers.
Construction is simple, use small aluminum miniboxes and a perf board prototyping board.
Use Phono jacks for In and Out, keep leads short. The recommended layout has the string of C1-C4 going up the middle of the board with L1 and L3 on one side and L2 on the other side of them to maximize the distance between the inductors. Tune by spreading turns on the toroids until the bandpass is centered in the middle of the band. I had to adjust the turns in some of the coils to get them to line up right, may be due to variations in capacitors or toroid cores. A spectrum analyzer would be nice.