Hotel de Ventes de Saint-Dié, France, sells on 11 June 2017 a "Flemish School, 2nd half of the 18th century" wine-making drawing, estimated at 200 to 300 Euro.
Christie's in 2009. It had been offered at the same auciton twice in 2008 with estimates of £6,000 to £8,000 first, and £4,000 to £6,000 second, but remained unsold both times. The third attempt, with a £2,000 to £4,000 estimate, was successful, and ended on £2,250.
Without further information on this, and without knowing the work of Helmbreker really well, I would tentatively suggest that this is not a late 18th century drawing, but an actual drawing by Helmbreker. This would mean that the estimate is way too low: even an "attributed" drawing fetched quite good money, 1800 Euro, while the two drawings at auction which were definitely attributed to him fetched 5,000 Euro and 35,000 Euro... If you can get this one for less than 1,000 Euro, you probably have a bargain.