There can really only be 2 models it could be. a) fully commercial 1 group machine (large / heavy / requires connect to mains water) and b) A semi commercial San Marino "Compact" in either of two configurations: i) older cube shaped body, stainless steel with gold looking trim around the cup tray at top ( from memory), lid over the internal water tank at RHS top, or ii) the later "CKX" model, a taller looking machine with stainless steel body, but with a black plastic top sitting over all of the top of the machine ie black plastic cup tray complete (and also with lid over the internal water tank at RHS top). Commercial machine definitely has a water pressure gauge, and from memory I think also the Compacts but if they are older machines I wouldnt necessarily expect them to still be working, especially on an older Compact which by now if described in human terms is about 120 years old and more than geriatric. Also if you are getting dry puks that come out reasonably solid and with the mark of the grub screw, then you are not underfilling the filter. After that, it is impossible to advise further without seeing what it is you are concerned about. I for one couldnt open the link you provided up top because my anti virus business "suite" decided it looked suspicious and blocked it. It's looking after me ;D I will say, if you put one of these machines next to a more modern / newer semi commercial machine (albeit retro style), then brew coffee using the same coffee, suitable grind for each and proper operator technique, you will notice quite a difference in the performance of the two machines. So....is your concern due to something you are doing, or is it to do with the possibility you may be using a tired old machine that may need some tweaking or upgrade, or could you get a better result by upgrading the grinder? I really dont know without having a chance to check it in the flesh.
