Google: old non-sef links change to new SEF ones

I currently host a mambo site with over 1600 photos. It has received 1300 hits from google in the past year and I am quite successfully ranked (over 2700 pages on site search) even though I was using non-SEF links (i.e. index.php?component=com_rsgallery&catid= etc.)

I have now recently changed to SEF links and have got everything running smoothly.

The problem: the 'old' non-SEF links still work in google. Will the crawlers detect the changes from the new links on each page? Or will they plainly look at the written content of that page and realise nothing has changed and won't update.

Is there any way using .htaccess to make google aware of my change to SEF? I can't possibly write rules for 2000 pages. Is there anything of the kind: "if incoming url contains ? or = to redirect to a 301 or 404 page?" Will google delete these pages?

I'm currently running mambo 4.5/1.0.9 with advance SEF (not the fully integrated version which works in 4.5.2 but just sef.php and .htaccess replacement files)

Thanks for any possible help