A brief update, I now use a product called "Atomic Tape" to seal the conduit to the fittings.  It works great and is not the least bit messy.

This series of photographics shows the completed installation of a new thru-deck for the mast wires. First, you see the completed project. Second, the female to male reducer which replaced the original Cape Dory "hole & silicon". And the third illustrates the mast end of the project.

Finally, having added coax and PL-259s for the masthead antenna, and wiring for a new anchor light, it got VERY crowded (too crowded) under the plywood cover (forward of the compression post) in the salon. To provide additional space I cut a "donut" of 1/2" marine plywood and placed it in a spacer position which solved the problem.

Materials for the thru-deck and the mast were purchased at Lowes. They only carry the "metallic" version of the conduit in 25' rolls at least in my area), so a helpful Lowes employee directed me to a local electrical warehouse where I was able to purchase 3' of "3/4 inch Liquidtight Flexible Nonmetallic Conduit Type B" to complete the process. The thru-Deck is a 1' to 3/4" reducer. The mast fitting is the male part to fit within the conduit. Use the bedding compound of your choice. The two ends of the conduit are sealed with Boat Life while I chose to use 3M 4200 for the thru_deck.

I got this idea from a "Workbench" article in Cruising World Magazine. Time will tell if it works and how well it stands up to UV damage and leakage. It seems to work much better the the original and IMHO it looks MUCH better.