You may not want to increase the number of variables you have to deal with, but if fresh coffee beans are not to be had then you should consider roasting your own. I'm reasonably confident that using the research of the roasting gurus on this site you could improve on stale, store-bought beans fairly quickly. You could start with minimal investment - an inexpensive heat gun used to strip paint works ok. My own roasting skills don't rival those of a professional, but it is fun, the resulting coffee is very good and you willl learn a lot about coffee in the process.

Well I spoke to the shop owner and he told me not to worry about the chirping/metal on metal noise and said that the grinder would continue to grind considerably finer than what I was doing. I pushed the grinder a bit further and my last attempt was 23s before blonding. I am not sure how this is affecting the burrs but the end result, for now, isn't too bad for me. It is fairly close to what I was getting with the Isomac and any further limitation will be my own skill and the beans, I think. Thank you all of you for your advice and patience.

Eric, I did consider that briefly but I am the only one in my family who shows much enthusiasm for espresso so when term starts again at university, it will all go ignored. Apart from that, nobody seems to sell green beans here. Maybe in future but for now I would like to get more comfortable with the machine and grinder first.