La conversión falló al convertir el valor varchar 'ninguno' al tipo de datos int

Si sus tablas en realidad consisten en Ninguno y NA, intente esto:

ALTER PROCEDURE spvec
AS
SELECT Row_number() OVER (ORDER BY (SELECT 1)) AS 'RNumber'
    ,vf.*
FROM LOGIN ld
    ,vehicle vf
WHERE (ld.fid = cast(vf.fid as varchar(max)))
    AND cast(ld.id as varchar(2)) <> 'NA'
    AND cast(vf.CustID as varchar(4)) <> 'None'
    AND cast(vf.Simo as varchar(4)) <> 'None'
ORDER BY Row_number() OVER (ORDER BY (SELECT 1))