plist file format is one of binary XML, plain text XML, or even plain text JSON. The
plist file that was posted in the question is the binary XML format.
One way to produce plain text from the binary file is as follows.
plutil -convert xml1 com.apple.SystemProfiler.plist
To convert the file back to binary, use
plutil as follows.
plutil -convert binary1 com.apple.SystemProfiler.plist
This would have helped to produce a better, plain text format for the question.
Assuming that "HV2J-en-GB_GB_4" is the right key, then the desired value might be acquired by using
PlistBuddy as follows. Note that wherever whitespace is encountered, single quotes can encapsulate text.
/usr/libexec/PlistBuddy -c "print :'CPU Names':HV2J-en-GB_GB_4" com.apple.SystemProfiler.plist
For the BASH script, one might put this value in a variable using command substitution.
model=$(/usr/libexec/PlistBuddy -c "print :'CPU Names':HV2J-en-GB_GB_4" com.apple.SystemProfiler.plist)
Afterward, the value is available in the variable,