A runner assembly (46; 146) comprising: a cradle (62; 162) comprising: a substantially planar base (72; 172) having a ring side, a runner side, a first end, and a second end, the base (72; 172) including a first fastener aperture (88A;188A) extending through the base (72; 172); a first finger (86A,86B;186A;186B) that extends from the first end; and a second finger (86C,86D;186C,186D) that extends from the second end; a runner (64; 164) comprising: a mounting portion positioned between the first and second fingers (86A,86B,86C,86D;186A,186B,186C,186D) and the base of the cradle, including a substantially planar cradle side that contacts the runner side of the base (72; 172); a contact portion with a curved contact side that is opposite of the cradle side; and a second fastener aperture (88B;188B) extending through the mounting portion and the contact portion; and a first fastener (66;166) extending through the first and second fastener apertures (88A,88B;188A,188B), the fastener (66;166) attaching the runner to the cradle; characterised by said cradle further comprising: a first tab extending from the first end, the first tab including a first tab aperture; a second tab extending from the second end, the second tab including a second tab aperture; a first bend at a junction of the first tab and the base; and a second bend at a junction of the second tab and the base; and wherein the first and second tabs (78A,78B) extend toward the runner side of the base (72;172). a cradle (62; 162) comprising: a substantially planar base (72; 172) having a ring side, a runner side, a first end, and a second end, the base (72; 172) including a first fastener aperture (88A;188A) extending through the base (72; 172); a first finger (86A,86B;186A;186B) that extends from the first end; and a second finger (86C,86D;186C,186D) that extends from the second end; a substantially planar base (72; 172) having a ring side, a runner side, a first end, and a second end, the base (72; 172) including a first fastener aperture (88A;188A) extending through the base (72; 172); a first finger (86A,86B;186A;186B) that extends from the first end; and a second finger (86C,86D;186C,186D) that extends from the second end; a runner (64; 164) comprising: a mounting portion positioned between the first and second fingers (86A,86B,86C,86D;186A,186B,186C,186D) and the base of the cradle, including a substantially planar cradle side that contacts the runner side of the base (72; 172); a contact portion with a curved contact side that is opposite of the cradle side; and a second fastener aperture (88B;188B) extending through the mounting portion and the contact portion; and a mounting portion positioned between the first and second fingers (86A,86B,86C,86D;186A,186B,186C,186D) and the base of the cradle, including a substantially planar cradle side that contacts the runner side of the base (72; 172); a contact portion with a curved contact side that is opposite of the cradle side; and a second fastener aperture (88B;188B) extending through the mounting portion and the contact portion; and a first fastener (66;166) extending through the first and second fastener apertures (88A,88B;188A,188B), the fastener (66;166) attaching the runner to the cradle; characterised by said cradle further comprising: a first tab extending from the first end, the first tab including a first tab aperture; a second tab extending from the second end, the second tab including a second tab aperture; a first bend at a junction of the first tab and the base; and a second bend at a junction of the second tab and the base; and wherein the first and second tabs (78A,78B) extend toward the runner side of the base (72;172). a first tab extending from the first end, the first tab including a first tab aperture; a second tab extending from the second end, the second tab including a second tab aperture; a first bend at a junction of the first tab and the base; and a second bend at a junction of the second tab and the base; and wherein the first and second tabs (78A,78B) extend toward the runner side of the base (72;172).