There is a replacement trigger for the Number 1
Brownells offers the Kepplinger set trigger for the Number 1. I sounds like from the reviews that the instructions are not great and there are casting marks that should be finished off prior to installation. The cost listed is 230 dollars. It is listed as being able to set the not set weight at 1-3 lbs.
One reviewer was not a happy camper, the other three were.