Dear Alan D,
this is a very interesting page on Your steadily growing Picasa encyclopedia - I gather from that - haven't got one - that these status quo sets will lock the pieces in place after sliding a metal plate across uder the board. Every bit helps, so I really appreciate these instructive picasa series of Yours...
Other peg sets rely on jamming the pieces in till You cannot get them out again!! Still, the Whittington type folding sets are easier to handle, when a bit damaged - just simple miniature carpentry and veneer artistry, or replacing an old screw tby a less old screw .. childs play really...
cheers
Nick