The seal is also called hood ledge anti-squeak, cowl lacing, hood lace etc. The Buick Master Parts Book shows it is GM part no 1195750. The only cars that use it are 1961-62 full size Buicks. A search by part number did not turn up any leads.
You may be able to find some bulk material from a supplier such as Steele Rubber which can be punched to accept the 10 fastener clips. The trick would be to match the cross section of the existing Buick part to their roll material or some reproduction seal for a car/truck of that era.
The clips are GM part no 4758423. That number was superceded by no 3767720. The 3767720 shown here is available as a reproduction item:
Choose Classic Muscle For Classic Chevy Parts - 1959-72 Impala/Chevelle/Nova Hood to Cowl Seal Retainer Clip set (15 pcs) - All The Classic Parts and Accessories You Need!
www.classicmuscle.com
Inserting a small flat blade screwdriver or needle nose pliers under the center of the clip should allow it to be pried loose. No special tools are called out for the clip in the shop or body manual. Typical GM vehicles using these clips are some 1960-63 GMC trucks, 1961-62 full size Pontiacs, 1961-64 full size Buicks, 1965 Riviera, 1962-66 Chevy IIs, 1964-66 Chevelles among others. These might be a starting place to search for seals with a similar cross section.