Bill: Good to hear from you!
Those are rare cast aluminum rocker box covers. Make sure you list them as such. They will fit anything from an A-50 through an O200 (Also 6 cylinder C-series and O- and GO-300, but you only have 4...) 4528 was the original part number. The stamped cover is 40762, although I believe that has been superseded to a 6 digit number now that the O200 is back in production. John Cooper Skyport Services 4996 Delaware Tnpk Rensselaerville, NY 12147 518 797-3064 www.skyportservices.net
