web tool about motifs in sandwich or barrel

Website: SMoS
Paper: http://peds.oxfordjournals.org/cgi/reprint/16/11/791

interlock in barrel?
http://www.ncbs.res.in/~faculty/mini/SMoS/02.02.092/02.02.092.htm

core of barrel should be four strands?http://www.ncbs.res.in/~faculty/mini/SMoS/02.02.092/02.02.092.htm
http://www.ncbs.res.in/~faculty/mini/SMoS/02.02.094/02.02.094.htm
or, strands face to face?http://www.ncbs.res.in/~faculty/mini/SMoS/02.02.097/02.02.097.htm