Hi, plans for rudder and centreboard are available from the Wayfarer Org. Secretary.
Class Rules mention this that may help.
Quote
17. CENTREBOARD
17.1 Material. Shall be solid or laminated wood or G.R.P. and shall comply with the official drawings and specifications.
17.2 Profile. (including any protective bands). Shall conform to official drawing.
17.3 Thickness. (Including protective coating). Shall be uniform. Maximum 21 (13/16?), minimum 17 (11/16?) except for permitted chamfer and packing.
17.4 Chamfer. Shall not extend more than 64 (2??) from any edge.
17.5 Edges. May be protected by metal or plastic bands of 10 (3/8?) maximum thickness.
17.6 Surface. Wooden centreboards complying with Rule 17 may have G.R.P. protection of approximately uniform thickness added. They shall then comply with Rule 17 in all respects.
17.7 Weight. Shall not exceed 6.123 (13.1/2 lbs). Weight concentration in any particular part of the centreboard is prohibited. This may be checked by flotation.
17.8 Angle. It shall not be possible to lower the centreboard beyond a position in which its leading edge is raked aft at an angle of 83 degrees to the tangent to the under surface of the keel at its point of intersection with the centreboard?s leading edge.
17.9 Depth. When fully lowered the bottom of the centreboard shall be not less than 965 (3?2?) or more than 1008 (3?3.5/8?) to underside of keel excluding the keel band.
17.10 A packing piece or packing pieces of equal thickness applied to each side of the centreboard shall be permitted. These will be included in the weight of the board. They shall not extend below the keel line with the board in any position.
18. RUDDER BLADE
18.1 Material. Shall be solid or laminated wood or GRP and shall comply with the official drawings and specifications.
18.2 Profile. (Including any protective bands). Shall conform to official drawings.
18.3 Thickness. (Including any protective coating). Shall be uniform. Max. 21 (13/16?), minimum 14 (9/16?) except for permitted chamfer.
18.4 Chamfer. Shall not extend more than 51 (2?) from any edge.
18.5 Edges. May be protected by metal or plastic bands of 10 (3/8?) maximum thickness.
18.6 Surface. Wooden rudder blades complying with Rule 18 may have G.R.P. protection of approximately uniform thickness added. They shall then still comply with Rule 18 in all respects.
18.7 Packing pieces of equal thickness applied to each side of the rudder blade shall be permitted. They shall not extend below the bottom of the rudder stock. The total thickness of the packing and blade shall not exceed 22mm.
18A. RUDDER STOCK
Material shall be wood or metal.
Wooden stocks shall comply with the official drawings and specifications. Metal stocks shall conform to the intention of the Class Rules (Rule 1.1) and shall be of a design approved by the local NCA.
End Quote.
Hope that helps.