Swiss Gold Coin And Brunei Proof Set Valuation Help

Swiss 20 Franc Gold Coin
also known as "Gold Vreneli"

The front says "Helvetia"
And the back says "20 Swiss Francs"

I had a collection of 52 mint condition Swiss issued Gold Coins with the following years;
1909 x 1
1911 x 1
1030 x 1
1922 x 2
1927 x 5
1030 x 1
1935 x 20
1947 x 16
1949 x 5

I also have some other set of three coins given to my father by the Sultan of Brunei. It is a proof set from the 1st of January, 1984. It comes with a Certificate of Authenticity stating the following;
"This is to certify that the coin set originally accompanied by this certificate is a proof set of the coinage issued in conjunction wit the Independence of Negara Brunei Darussalam on the 27th day of Rabiulawal 1404 Hijrah corresponding to 1st January 1984. The set which is composed of a ONE THOUSAND DOLLARS coin weighing 50 grammes and containing 916.7 fine gold, a ONE HUNDRED DOLLARS coin weighing 28.28 grammes and containing 925 fine silver and a TEN DOLARS eupro-nickel coin, was minted in limited edition by The Royal Mint under the authorization of Brunei Currency Board. These coins are legal tender in Negara Brunei Darussalam.
Date: 1st January 1984"


And help if finding a valuation for these coins would be very much appreciated. Thank you for your help!

-Thomas