pdfmark in Lout

Hello,

Has anyone managed a reasonably comprehensive implementation of
pdfmark within Lout (including textbox, checkbox, listbox etc.)? 

Specifically, I have to produce some pdf versions of hard copy forms
that I have created in Lout. To this end I have created a Lout
function that implements a textbox (which is good enough for my
limited needs) but wondered if anyone else had other bits that could
be combined to form an "official" pdfmark functionality, assuming it
does not already exist and I have just missed it...

Kind regards,

Tristan Williams