Please help identify this movie

Cafe Society
1

History has fogged my mind. Any or all of the clues I have may be imagined or erroneous.

I’m rememdering a scene from an old movie where one of the plot points is the protaganists talking loudly in a public place to entice criminal intervention.

Alleged facts:

  1. An old British Movie.

  2. Possibly Black & White.

  3. Possibly an Ealing Comedy.

  4. The revelation could have been in a Bar or on a Train.

  5. Possibly with Alec Guiness and/or Cecil Parker.

“Fact” 5 might just be my mind filling the blanks from “facts” 1-4

2

The Titfield Thunderbolt.

3

“The Titfield Thunderbolt”

I don’t think so.

I remember the protagonists were intimating that something of value (a jewel/money) would be being transported by x from a to b on date d.

4

The Lavender Hill Mob.

Definitely. I was watching it on Sunday.

5

Ding Ding Ding

Promethea you have it - “Lavender Hill Mob”

Alec Guiness and Stanley Holloway are fishing for Sid James and Alfie Bass

Thanks.