Continental Enterprises have been manufacturing Continental kits for Tbirds, Fomoco and some 200 other vehicles since 1976. Here is a special announcement from them.
'58-'60 Squarebird Continental Kit Special Offer: $1,695.
To view that top ad better use Ctrl+ to expand it. I had to downsize it to upload it.
Here is their contact information. Their email address is: firstname.lastname@example.org