Unless there was a problem during the installation of the latest update, these settings shouldn't have disappeared. My latest update to R 49.29 didn't run into any problems. In the list of active register columns in your register, is "Action buttons" enabled?
That should give you the missing icons back.
Re-customize the Action bar to add buttons for one-click access to New Vendor Invoice, New Payment, etc. From the Action gear icon in the register select "Customize Action Bar" and then add the desired toolbar buttons. Here are my settings as an example:
