No sets to upgrade the original M2 to ODS standards. But, Tamiya does sell individual sprues to their models. You can call them and order the M2A2 sprue and the ODS sprue along with the new square block track that comes in ODS kit. The sprues go for about $5 each. I bought the track and ODS sprue to bring the Tamiya M2A2 up to the ODS standard. They ship quickly and shipping is cheap within the US. Here is their contact info: http://www.tamiyausa.com/contact/index.php
Here is a great site with an extensive article on corrections and further upgrades that can be done to the M2A2 and M2A2 ODS kits to make them more accurate as well.
http://www.vodnik.net/
M2A2 article: http://vodnik2.republika.pl/pages/m2a2/m2a2-p1.htm
I used the above method to build my M7 B-FIST that I recently posted on this site, you can see it here in this thread.
http://www.finescale.com/fsm/community/forum/topic.asp?TOPIC_ID=30277
Good luck.
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