Walker & Hall Teapot

I have a silverplate Walker & Hal teapot, there is the number 6 obove the W&H in a flag, underneath the W&H flag is a diamond divided into 4 diamonds, the top diamond has the Sheffield crown, left diamond looks like old english letter M, right diamond old english letter J and bottom diamond old english letter R. Underneath that in a circle it written patent handle with the number 3245 in the middle of the circle. Beneath that is the number 536 and under that is the number 73.
The teapot was bought from England by my Aunty Alice Kent who jumped ship when it was sinking on her way to Australia. She grabbed the teapot apparently and was saved from drowning ny her crinoline dress. She has very faintly scratched her name inthe the base of the teapot. The pattern is very ornate and the handle has heat escaping holes. The knob on the hinged lid is held on by a small wing nut. It is an oveal shape. Can you tell me the history and what the marks on the bottom of my teapot mean please?
hallmarks.jpg
silver teapot.jpg