Your blog is at thread number 65647 and you'll find the cached posts for much of it using the google search term:
aussiefrogs showthread.php?t=65647
All pages share the same thread number.

(Edit: Now found page 1 at:
http://cc.bingj.com/cache.aspx?q=aussiefrogs+thread.php%3ft%3d65647&d=4835501951352977&mkt=en-AU&setlang=en-AU&w=da2e512f,83b8b337
End Edit)

Page 2 is cached here (copy the whole link):
http://webcache.googleusercontent.com/search?q=cache:K58q2XIwOMgJ:www.aussiefrogs.com/forum/showthread.php%3Ft%3D65647%26page%3D2+site:aussiefrogs.com+aussiefrogs+showthread.php%3Ft%3D65647&cd=1&hl=en&ct=clnk&gl=au

(Edit: Page 3 exists via Bing (MS version of Google) and is here:
http://cc.bingj.com/cache.aspx?q=aussiefrogs+showthread.php%3ft%3d65647&d=4519070243294550&mkt=en-AU&setlang=en-AU&w=40502f52,686acd6b
End edit)

Some of the other pages seem to be cached at Google, but not all apparently. You have to look for the word 'cached' at the end of each entry and open it in a new tab. Save the whole page in whatever format suits, but the ".mht" option works. Page 2 includes a lot of pictures because they were originally posted inline.

It's also possible to find the cached summary pages for each forum by page. They are not necessarily up to date and the links obviously won't work, but you can at least extract the thread number of a topic of interest and then search for for it. Try the search term:
"http://www.aussiefrogs.com/forum/forumdisplay.php?f=11&order=desc&daysprune=-1&page=2"
This will find the cached page 2 of the Citroen Forum from August. 11=Citroen, 12=Peugeot, 13=Renault, 14=Chat,15-Cars, 18=Parts. The Pond (26) and Humour (16) fail to find anything, so they are probably not cached.