Good evening, Sebastian,

Thank you for contacting Mearto with your appraisal inquiry. I have not been able to find an artist 'K.William' with a matching signature or working in this particular style but based on the photographs and information provided, this is:

American School, Late 19th Century
Still life (Flowers in a Vase)
oil on canvas, 42" H by 29" W
signed "K.William" lower right, verso marked " FL610/78"
$300-500

Please let us know if you have other items to appraise, and thank you for using Mearto.