Monkey King painting

I bought this painting on Ebay in 2004. Labeled "Great Sage Equaling Heaven" (ink and colors on paper, 28 x 47 in), it is a painting of Sun Wukong the Monkey King from the highly popular 16th century Chinese novel Journey to the West (西游记, Xiyouji), or as it is known in Japan, Saiyuki. It depicts the immortal monkey during his battle with the heavenly army. The inscription and red block seal states that it was painted by the female artist Yang Ruifen of the Tianjin Academy of Fine Arts in Autumn of the Jiashen year (i.e. 2004). Jiashen refers to an ancient Chinese dating system that assigns elements and animals to each year within a 60 year period. It coincides with the "Yang Wood Monkey."

I recently discovered (as of late 2016) that the piece is based on one of several paintings appearing in the book Journey to the West: Havoc in Heaven (西游记之闹天宫, Xiyouji zhi nao tiangong) (1956) by noted artist Liu Jiyou (刘继卣, 1918-1983). Scans of the paintings can be seen here.

seetobe.tumblr.com/post/713029…

One of Liu's pieces is a direct copy of one of the many 19th-century paintings adorning the crossbeams in the Long Corridor of the Summer Palace in Beijing, China. 

Liu's painting: imageshack.com/a/img924/2576/7…

The Long Corridor painting: upload.wikimedia.org/wikipedia…

This suggests the artist drew the inspiration for his paintings from this place.