I have a happy customer!
Managed to resolve this after much testing and customer is successfuly printing reports from his DOS General Ledger package to his to his USB windows laser printer.
The solution which worked was to install 'winprint' software utility which captures the output from LPT1 and directs it to the windows printer.
He can now print portrait, landscape and double sided and most importantly, ditch his dot-matrix printer! So is very happy.
Once I determined that was the solution, it took me less than 5 mins to install the SW and have it up and running.
Thanks bobafetthotmail for bringing that software to my attention and thanks all who gave input.
Btw. As far as availability of laser printers with parallel interfaces, there are several slightly older Brother printers still around that provide that connectivity.
Who knows, this may help somebody else faced with same issue.