These thumb throttles are pretty nifty. They make one with dual brake pull lever and has a brake lock and light switch built in. All metal, cost around $16-20. Mine survived the wreck no problem
I use them for all my kits I sell and they perform well. Smooth action and a well thought out set up with in line adjustable barrel.
Be sure to find them with cables or separate. They make different sizes check it out on Amazon.
OXYVAN Bike Seat Most Comfortable Universal Replacement Bicycle Seat Cushion Dual Shock Absorbing Ball Wide Bicycle Saddle for Men Women, Green https://www.walmart.com/ip/537461782
OXYVAN Bike Seat Most Comfortable Universal Replacement Bicycle Seat Cushion Dual Shock Absorbing Ball Wide Bicycle Saddle for Men Women, Green https://www.walmart.com/ip/537461782