Morris London watch mystery

[Jimbo1952]

I was recently clearing out my sisters’ house when I came across this very dilapidated pocket watch.
It is obviously in a very poor state of repair with no hands and broken and cracked enamel face.
What piques my curiosity, is it is in a silver case, rather, it is in a silver case within a silver case. The marks on both cases would seem to indicate a London assay office with a date letter that would appear to be either 1761 or 1841, the makers initials I cannot identify.
The problem with these dates is that the watch mechanism as can be seen gives a date of 1900, could it be that the case and mechanism were not originally paired together?
Also confusing although it was probably a later repair is that the “lens” is made of plastic.
Unfortunately, my sister has dementia and is in no condition to give any information as to the watches provenance.
I would love to know a little bit more about this and would be really grateful if anyone can give me any information.

https://imgur.com/HRw431r
https://imgur.com/D3UcfDt
https://imgur.com/KB5WfCT
https://imgur.com/J8H4WCB

[dognose]

Hi,

Welcome to the Forum.

Please embed your images.

Trev.

[Jimbo1952]

Apologies, bit of a novice in this Forum thingy.

[dognose]

They are a little on the small side........

Trev.

[Jimbo1952]

Apologies in advance if I have made these too big.
Many thanks for your help

[silvermakersmarks]

The date letter is that for the assay year 1761/62. I note that the watch movement does not seem to fit too snugly into the case so the mechanism and case may not necessarily be from the same period. We are unable to identify the case maker; it is not shown in any published list of London marks and it is therefore likely that the mark registration was recorded in the 1739-1758 Smallworkers' Register which has unfortunately been lost.

Phil

[Jimbo1952]

Phil, very many thanks for this information.
I am very grateful.

Jim