An old version of firefox for slower machines?

I've been thinking about this for some time now- I have a very old laptop, a Vaio PCG-505RS. Its from 1998, but works quite well, albeit slowly. I haven't tested the firewire port, but otherwise I've gotten most of it up and running.

The problem is, of course, surfing the web. Running Firefox is... troublesome, since it consumes almost 50M, on this 64M RAM machine.

I've tried running dillo, which is, as they say, fast and lightweight, but it has pretty much no support for CSS and the like.

Which has gotten me thinking.. what if I install one of the original versions of firefox onto this laptop? The first version of Firefox, then called Pheonix must have been lightweight. At least I don't remember it hogging lots of memory. On the other hand, at the time I was probably too excited about a possible contender to Internet Explorer to be too picky about 'details' such as memory usage.

Anyway, I started looking around, and found this site, which seems to have all of them, precompiled. What I want is the source, but a quick look around the mozilla.org site didn't turn up any results.

I wonder where I can get the source for pheonix 0.1?