Conjectured 22×22 {-1, +1} matrix of maximal determinant

Ratio of |Det R| to Ehlich/Wojtas bound: 0.952381

M=R^TR=R R^T:

22  2  2  2  2  2  2  2  2  2  2  2  0  0  0  0  0  0  0  0  0  0
 2 22  2  2  2  2  2  2  2  2  2  2  0  0  0  0  0  0  0  0  0  0
 2  2 22  2  2  2  2  2  2  2  2  2  0  0  0  0  0  0  0  0  0  0
 2  2  2 22  2  2  2  2  2  2  2  2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2 22  2  2  2  2  2  2  2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2  2 22  2  2  2  2 -2 -2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2  2  2 22  2  2  2 -2 -2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2  2  2  2 22  2  2 -2 -2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2  2  2  2  2 22  2 -2 -2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2  2  2  2  2  2 22 -2 -2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2  2 -2 -2 -2 -2 -2 22  2  0  0  0  0  0  0  0  0  0  0
 2  2  2  2  2 -2 -2 -2 -2 -2  2 22  0  0  0  0  0  0  0  0  0  0
 0  0  0  0  0  0  0  0  0  0  0  0 22  2  2  2  2  2  2  2  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2 22  2  2  2  2  2  2  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2 22  2  2  2  2  2  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2  2 22  2  2  2  2  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2  2  2 22  2  2  2  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2 22  2  2  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2  2 22  2  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2  2  2 22  2  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2  2  2  2 22  2
 0  0  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2  2  2  2  2 22

R:

++-----++++++++++-----
++-----+++++-----+++++
--+----+----++-----+-+
---+----+----++--+--+-
----+----+--+---+-+-+-
-----+----+---++--+--+
------+----+---+++-+--
+++----+------+-+++---
++-+----+---+--+--++--
++--+----+---+-+-+---+
++---+----+--+--+--++-
++----+----++-+-----++
+---+++++-+-+----+----
+-+--++-++-+-+----+---
+--+++-+-+-+--+----+--
+-++--++-++----+----+-
+-+++---+-++----+----+
-+++-+---++++----+----
-+-++-++--++-+----+---
-++-+-+-+++---+----+--
-++-++-++--+---+----+-
-+-+-+++++------+----+

Notes:

1. Cannot achieve Ehlich/Wojtas bound since 21=22-1 is not the sum of two squares.
2. This form has not been proved to be optimal.
3. This lower bound was reported by Dowdeswell, Neubauer, Solomon and Tumer [DNST].
4. Are M and R unique (up to equivalence)?