So, I'm not sure if this will help any, but I have three variants of the Bolton boats; 13", 11" & 6.25". All three of them have Rd 39414 on the back end of the boat.
The 11" boat has the words Grace Darling on the back, as well as Rd 23527 and the
Grace Darling
Boat
_._
Rd 23527
in the base. I took it to mean that they'd registered 23527 as the "Grace Darling Boat" to prevent other people using the name, whilst the general shape and pattern was 39414.
I think the people of that time, were just shocked as anything that a woman rowed a boat and rescued people. Hence why they created a commemorative boat 50 years later. The RNLI have a page about her https://rnli.org/about-us/our-history/timeline/1838-grace-darling