I developed LSX at Bell Labs in Murray Hill NJ in the 1974-1975
timeframe.
An existing C compiler made it possible without too much effort. The
UNIX
source was available to Universities by then. I also developed Mini-UNIX
for the PDP11/10  (also no memory protection) in the 1976 timeframe.
This source code was also made available to Universities, but the source
code for LSX was not.

Peter Weiner, the founder of INTERACTIVE Systems Corp.(ISC) in June
1977,
the first commercial company to license UNIX source from Western
Electric for $20,000. Binary licenses were available at the same time.
I joined ISC in May of 1978 when ISC was the first company to offer
UNIX support services to third parties. There was never any talk about
licensing  UNIX source code from Western Electric (WE) from the founding
of ISC to when the Intel 8086 micro became available in 1981.
DEC never really targeted the PC market with the LSI-11 micro,
and WE never made it easy to license binary copies of the UNIX
source code, So LSX never really caught on in the commercial market.
ISC was in the business of porting the UNIX source code to other
computers, micro to mainframe, as new computer architectures
were developed.