[filch]

Of course, no sooner had I hit submit when I came up with an answer. Not sure if this is the best way but it seems to work for me and not affect other areas. I simply changed the $lng variable in continue.tpl to the value of a new label I created, reflecting the text I wanted. i.e.

{include file="buttons/button.tpl" button_title=$lng.lbl_process_payment href=$href title=$title style=$style}

The area in bold is the new label I created in admin with the text value of "Process Payment".

HTH someone.

Dave