They’re a reseller & he’s saying he doesn’t have one in stock. The visorshop (Crossan’s Motorcycles) in NI seem to have one. https://www.thevisorshop.com/en/ie/JT-Front-Sprockets-JTF740-14-DUCATI/m-3444.aspx Personally, I’m a fan of changing the rear (and chain if needs be) rather than the front sprocket, for a variety of reasons but everyone has their own views and experience. However, what you’re experiencing is normal. I’ve had my ST2 for 7 years now. I bought it cheaply as a project bike, actually really liked it and haven’t yet got around to the ‘project’, maybe one day. Just leave it in 1st or 2nd in town and feather the clutch. Leave the sprocket change until it’s time for a new chain & sprocket set.
I'm not sure how much help this will be but on the Aprilia RSV standard is 17/42 and can be difficult around town, an accepted mod is to go to 16/44 which smooths the riding round town considerably. You lose a small amount of top end but for my mind it's an acceptable compromise. The point is that sometimes it is better to adjust both sprocket sizes to achieve your goal. The added bonus is it's much easier to wheelie
Thanks Paul, that sounds like pretty good advice for the time being albeit there have been many very interesting and helpful posts on here for which I thank all contributors.