Avengers: Infinty War Looking for Extra Casts in UK

It appears that filming for Avengers: Infinity War and the still-unnamed Avengers 4 has wrapped in Atlanta, at least for the time being, and is moving across the pond to filming in the United Kingdom.
As per MovieCastingCall.org, the production is looking for extras, stand-ins, and photo doubles. As the casting call states, all actors and extras must be legally eligible to work in the entertainment industry in the United Kingdom.
The casting then goes on to list additional details in regards to three specific roles:
  •     MALES & FEMALES – Ages 16 – 90 years. All types any ethnicity. No experience necessary. You must have easy access to Edinburgh or the surrounding areas for filming.
  •     MALE ARM AMPUTEES – Ages 30 – 40. You must be an arm amputee. You must have easy access to London. Filming Dates: Monday 20th March and Wednesday 10th May 2017.
  •     MALES & FEMALES 4’9″ OR SMALLER – Ages 16 – 90 years. You must be 4’9″ or smaller. You must have easy access to London. Filming Date(s): you must have good availability for filming in March 2017.

While the first role seems to be a generic casting for extras, the two roles that follow are rather detailed looking for very specific actors.
Avengers: Infinity War is being directed by Joe and Anthony Russo, from a screenplay by Christopher Markus & Stephen McFeely. The film sees the Avengers joining forces with the Guardians of the Galaxy to battle Thanos.
Avengers: Infinity War’s confirmed cast includes Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Benicio del Toro and Tom Holland.
Avengers: Infinity War opens in theatres on May 4, 2018.
Source: Comicbook