Mark, the 733 is a fairly easy beastie to dismantle and clean. I recommend you firstly wind the caqrriage UP as far as it will comfortably go, them whip off the handle and the four allen/hex key headed bolts holding the shell onto the main body. (All that is clearly visible on the top cover). Then, up-end the assebmly, CAREFULLY! as the metal posts waggle ever so slightly, and you should be able to get limited access to the rollers for cleaning. You'll probably get dead annoyed as the tables start to droop down into your way, but what I have described is the least you can do to gain access. A more involved stripdown is quite straightforward, you can see where to go from here by casting an eyeball over the various fittings.
Sam
PS You don't need expensive solvents to clean pitch or resin from machinery; a judicious mix of diesel/heating oil and white spirit, with maybe acetone(nail varnish remover) or meths for lighter compounds will, given enough time, soften most problems.