Ken Sheffield, 1982
Longways for as many as will
Video: https://www.youtube.com/watch?v=a_41-6KfpeI
Recording: sun_assembly--043.mp3.zip
sun_assembly-vemh-16.mp3.zip

Published in 1757 in Thompson's Compleat Collection of 200 Fashionable Country Dances and interpreted Ken Sheffield in 1982. The dance appears earlier in Johnson, 1751 A Choice Collection of 200 Favourite Country Dances, Vol 6.

Original instructions are not quite the modern variant.

First and 2d. Cu Hands all 4 circle half round and back again Cross over half figure and foot it and turn 1st. Cu. Hands round with the 3d. Cu. and then with the 2d. lead thro' the 2d. Cu. cast off and turn your Partner

   A     8  Hands four half-way; and fall back with corner
         8  "Gate": (First couple leads up one place and casts back, assisted
            by second couple)
         8  First couple half a figure-eight up through second and back to 
            second place, as second couple cross up on last 4 beats
         8  Set and turn single
   B     8  First couple right hands across with couple _below_
         8  First couple left hands across with original second couple
         8  First couple lead down through next couple and cast back to place
         8  Turn partner, both hands.

See an animation of this dance.

A 1-4 Ist and 2nd couples circle four-hands around half-way and fall back. 
      5-8 Keeping inside hands: Ist couple turn with neighbor, 1st couple moving forward,
          2nd couple backing up, pivoting around the point between them, all moving 
          to progressed place, improper.
      9-12 Ist couple half figure-eight through the couple above, who change places 
           after 1st coup! goes through.
      13-16 All set and turn single.

B 1-4 Ist couple right hands-across with couple below.
  5-8 Ist couple left hands-across with couple above,
  9-12 Ist couple lead through couple below and cast up to progressed place.
  13-16 Partners turn two-hands.

SUN ASSEMBLY
A Sun Tavern was located near the intersection of Gray's Inn Road and High Holborn, near the corner of Brook Street, Daniel Wright, musical instrument seller and dance book publisher, had his shop next door. Perhaps the establishment had a large room for dancing parties. This title may refer to a subscription series at the Sun, The little page of the volume in which the dance was printed gives a good picture of a dancing party at mid-century.