Silver Content Of US Mint Proof Sets

Well, you can look up individual coins in the RedBook for "weight in Silver".
The 1964 Kennedy Half (and modern Silver version) has the same Silver weight as the Walker and the Franklin.....which is .36169 oz. pure Silver.
You're just talking Proof Sets.....but the older "Draped Bust" half has .8924 oz. Silver, which of course wouldn't be in a "Set".

Quarters have .18084 oz pure Silver ......modern and pre-'65 standards are the same

Dimes are .07234 oz. pure Silver....and pre-'65 standards are the same.

Ikes (where they are Silver and in a Set) are .3161 oz pure Silver.

Of course there are many coins in the Modern Sets that aren't Silver. The Cent, the Nickel, the Native Dollar, the Presidential dollar.
It would just be the Half, the Quarter, and the Dime that's Silver.

Here's a Coin Values Calculator that lists the Troy oz. content of each coin.

The Dimes, Quarters, and Half-Dollars in 1992-present Silver Proof Sets
are 90% Silver, and thus are the same content as their pre-1965 counterparts.
(so you can calculate them with the "1964" values)

Example: A 2009 Silver Proof Set has eight 90% Silver coins.
One Dime (0.0723 oz.), Six Quarters (1.0851 total oz.),
and One JFK Half-Dollar (0.3617 oz.)

Total Silver content for the 2009 Silver Proof Set is 1.5191 Troy Oz.

1992-1998 Silver Proof Sets (one each Dime, Quarter, and Half-Dollar)
have .6148 Troy Oz. total Silver content.

There may be occasions at big coin shows or on ebay when Silver Proof
Sets (particularly pre-1999 Sets) may be sold for not much above
their 'melt value', so this can be very useful information.

Unlike 'junk silver' (pre-1965 circulated coins), Proof coins (that
are still in the OGP lenses) are not worn from circulation, so they
have not lost weight from wear.