The following list can be summarized in short.
    1.)  Rev counter cable is 8-inches shorter for LHD than for RHD.
    2.)  The tach and speedo cables had a change of materials and part numbers at (c)17588 (1500 model prior to Twin Cam). The newer parts supersede the older part numbers.
    3.)  The speedometer cable was made 3-inches longer to accommodate high starter position at (c)61504.
    4.)  Tach cable had a change of part number at (c)68851 (start of 1600 model).
    5.)  Speedo cable for RHD cars had a change of part number at (c)74979. (Nature of the modification is unknown).
    6.)  Twin Cam cable changes are concurrent with the standard models.
    7.)  Unless otherwise specified, cable length is the outer jacket face to face.

   MGA 1500:
AHH5353  Cable - rev counter (4' 0" RHD)  1B9141    | com.(c)17588
  7H1695   Cable inner                      17H630  | com.(c)17588
  17H220   Cable outer                      17H1343 | com.(c)17588
AHH5354  Cable - rev counter (3' 2" LHD)  27H1801   | com.(c)17588
  17H218   Cable inner                      27H1860 | com.(c)17588
  17H219   Cable outer                      27H1861 | com.(c)17588
AHH5292  Cable - speedometer (5' 3")      27H1393   | com.(c)17588, fin.(c)61503
  7H1694   Cable inner                      17H1346 | com.(c)17588, fin.(c)61503
  7H1221   Cable outer                      27H1391 | com.(c)17588, fin.(c)61503
ACC8788  Cable - speedometer (5' 6")                | com.(c)61504 (high starter)
  17H756   Cable inner                              | com.(c)61504 (high starter)
  17H757   Cable outer                              | com.(c)61504 (high starter)

    MGA 1600:
1B9141   Cable assy - rev counter (4' 0" RHD)       | Part no. change was ACC8788
  17H630  Cable inner
  17H1343 Cable outer 
27H1801  Cable assy - rev counter (3' 2" LHD)
  27H1860 Cable inner
  27H1861 Cable outer
27H1393  Cable - speedometer (5' 3" RHD)  BCA4079   | com.(c)74979
  17H1346 Cable inner                       17H1346 | com.(c)74979
  27H1391 Cable outer                       17H1586 | com.(c)74979
1B9138   Cable - speedometer (5' 6" LHD)
  17H756  Cable inner
  17H757  Cable outer

    MGA Twin Cam:
1B9141   Cable - revolution counter (4' 0") (RHD)
  17H630   Cable inner
  17H1343  Cable outer
27H1801  Cable - revolution counter (3' 2") (LHD)
  27H1860  Cable inner
  27H1861  Cable outer
27H1393  Cable - speedometer (5' 3")  | fin.(c)712 (LHD), fin.(c)2466 (RHD)
  17H1346  Cable inner                | fin.(c)712 (LHD), fin.(c)2466 (RHD)
  27H1391  Cable outer                | fin.(c)712 (LHD), fin.(c)2466 (RHD)
BCA4079  Cable - speedometer (5' 3")  | com.(c)2467 (RHD)
  17H1346  Cable inner                | com.(c)2467 (RHD)
  17H1586  Cable outer                | com.(c)2467 (RHD)
ACC8788  Cable - speedometer (5' 6")  | com.(c)713 (LHD)
  17H756   Cable inner                | com.(c)713 (LHD)
  17H757   Cable outer                | com.(c)713 (LHD)

    Sundries:
PRC0709  Clip - cable to bulkhead
ACH8529  Sleeve - clip (rubber)
FNZ104   Nut fixing clip (to RH toeboard screw)
LWZ204   Washer - spring (clip to RH toeboard screw)
ACB8474  Grommet - cable through bulkhead
4G2541   Grommet - blanking cable hole in bulkhead

    T9 5-speed:
Hi-gear Engineering supplies only one length for RHD and LHD:
  Cable outer = 2140mm (7' 0-1/4")
  Cable inner = 2155mm (7' 0-7/8")
This is intended to be long enough to run under the seat on right side before 
looping forward.  If a right angle gearbox is used to run the cable forward 
within the tunnel, then a shorter cable can be used.