Try Jeff Kane at Ttender.com. He lists wheel sets as part number 1661DW or 1661Z. They my be smooth or knurled hole for axle, so I would ask first. The Smooth axle is AM-84 for the 8 spoke (Lionel Jr. Series), and the knurled axle is 1689E-27. The 8 spoke wheels are hard to come by, and typically in the $40 range and only sold as complete set of four. The 8 spoke were usually reserved for Lionel Jr. (1936 only), used on 1661/1681/1688E/1689E in 1936. Lionel transitioned to 10/12 spoke wheels starting in 1937.