I’m adding this post just as a reference to the first old newspaper article I can find that mentions the Skegness Cricket Ground. This was in the 22 August 1874 issue of the Herts Advertiser – St Albans, Hertfordshire, England, where it refers to the NEW cricket ground at Skegness. This suggests it opened in Summer of 1874. It refers only to the GROUND, not mentioning the Pavilion at all.
I cannot, as yet, find an official opening story, but will continue looking….