Re: Actually not much like the Shuttle at all
"copy of an idea the Russians were trialling in the 1980s"
Your timeline is a bit off.
Russia had Buran in the 80s, which was a reply to the US Space Shuttle.
Before both systems were the US lifting body experiments, plus the Dynasoaur, and the Soviet BOR and MiG-105 testbeds, all starting in the '60s. The soviets were trailing in this research, the USA was trialling lifting body aircraft in the early '60s, whereas the MiG-105 wasn't until 1969.
Dreamchaser however does strongly resemble the MiG-105.