are the lower guides blocks, I can't quite see. If so, you can probably buy replacements called "cool blocks" which were an aftermarket upgrade. I think they were a ceramic of sorts. Alternatively if yours need replacing or tidying up, you can make them out of lignum vitae. a pen blank or a bowling ball is a good source of this, but you only need a couple of small offcuts.
for the upper guides, I would expect that they are a very common bearing size and will cost you between a few pence and a couple of quid depending on quality so if they dont spin perfectly they are a quick and cheap job to replace.
nice little saw, I am sure it will do you well.