You are correct, original HS carb and the needle has never been changed under my ownership. The only mods I can see are an upgraded exhaust manifold and a minispares intake. Newish cap, wires and coil on the car as well.
I check the dashpot oil pretty regularly and try to keep it a few mm's above the plunger (kind of at the level where there is a little flat spot on the rod). But, that being said, the previous owner used ATF instead of dashpot oil in it. But the engine ran pretty good so I never bothered to change it out for the correct stuff. Also, I live in Canada so local parts are far and few between for me and any part I need is typically 2 weeks away minimum and comes from the UK.
Totally different world from when I was messing with a 6.7 Cummins intake manifold—not nearly as easy to source parts for this little guy.
ATF isn’t a big deal—plenty of people run it without problems. With that intake and exhaust setup though, the stock needle might not be ideal anymore. If it feels a bit lean or flat, swapping to a slightly richer needle could help smooth things out.