All user reviews for the Matthew Lindsay 7607

You're attributing the 7607 to Matthew Lindsay. This is incorrect.

The actual designer was Paul Lindsay. He also designed a spectrum analyzer and built mixing desks for Mike Oldfield.

I know this because I worked for him from 1977 to 1981 and there's a really high chance I built the units in your photograph.

Please see attached image of the rear of a unit that clearly shows Paul's name.