Based on what I read, my guess is the Horizontal output has blown... may have taken out the power supply.
I could not find an NTE repalcement for the part#'s you gave so it is hard to say what comes next.
I would not spnd a lot, the monitor is old... we do not carry 19"CGA as there is no way to compete with the cheap offerings.
I would suggest you contact Betson.
Rick@niemandisplays.com