[Xenon]

no prob

just replace

AND dateline > " . (TIMENOW - 3600) . "

with

AND dateline > " . (TIMENOW - 3600) . " AND dateline < " . (TIMENOW - 600) . "

as well as replace

PHP Code:

AND $threadinfo['lastpost'] > TIMENOW - 3600 


with

PHP Code:

AND $threadinfo['lastpost'] > TIMENOW - 3600 AND $threadinfo['lastpost'] < TIMENOW - 600 


as for the merging text addition:
in

PHP Code:

$post['message'] = $doublepost['pagetext'] . "\n\n" . $post['message']; 


replace the "\n\n" with for example:

PHP Code:

$post['message'] = $doublepost['pagetext'] . "\nAdded at " . vbdate($vboptions['dateformat'], TIMENOW) . "\n" . $post['message'];