Thank you Teejay. As you observe the "slower" modules are super inexpensive so I intend to purchase a pair and see how that improves performance. It does seem that the 333 MHz was standard according to the manual: 256-MB DDR synchronous DRAM (SDRAM) at 333 MHz,
expandable to 2.0 GB or 1.0 GB, varying by notebook model

Thanks everyone for your suggestions. I've been made to feel very welcome.
Teejay, a question based on your comment "DDR 266 SODIMMs are inexpensive these days". I've pulled the RAM from machine and it's 333 MHz (not 266 as you recommend). I'm wondering if 2 GB of a slower RAM would still be a good investment? The price of equivalent 333 MHz RAM is too expensive to consider on such an old machine.
To everyone else I will work through and attend to your suggestions. I'm determined to give it my best shot.

Thanks to both of you for your assistance and advice. Perhaps this needs to be in a different post, but I've tried running Microwatt R9 32 bit and it fails to run in Live Boot. The boot screen appears, automatic boot in 1 second appears, 7 lines of dots appear across the screen, then nothing further. Perhaps Microwatt isn't ideal for machines as old as this?