Welcome Waroros - nice looking machine.* Like all E61s you would need to give it at least 30 to 45 minutes on its own to get all that brass up to temperature and stable.* You can speed this up with a few heating flushes of water through the group but its a bit of guess work as to how much is enough.
My theory is that weve paid extra for all that "old school" bling, that bling needs some "old school" time to allow the laws of thermodynamics to do the magic that keeps the E61 "up there" after 50 years, so I plan ahead.* You could also get a timer.