Thanks for the reply.
Just checked out the Ronco Web Site.
http://www.ronco-plastics.com/newRonco/categories.php?catID=1
They have many options listed. Holding Tank on Hunter 40.5 is odd ball size and shape.
I need to go back into the forum archives and find drawing of tank to do some comparison. Probably still going to end up going with custom build for the tank, would prefer it to be as large as possible and fit into the space it needs to fit. There is link on Ronco site for custom tanks. Will send them the drawings once I have and see what the cost is.
Really would like to replace tank with plastic but just might go with aluminum. What the heck, the original lasted 16 to 17 years.
I have placed this project on the back burner till this winter as need to get the bottom job done in next week or two. Boat dollars are going to the bottom maintanance at this point.