Cut and installed Van's access panel flanges following OP-43 instructions. Did this work in Jan prior to leaving on 6 wk vacation. Just prior to leaving, used pro seal and plastic bag to make gasket following instructions. Allowed pro seal to cure while away for 6 weeks. Today, I removed the plastic, trimmed the excess pro seal, and screwed down the two access plates. Cleaned residual pro seal with acetone. Installed left step.