With thanks to Michael Browning for the following snippet.
” I’ve been researching the Allan family and was interested to read Stewart Thomson (Courtside) and Martin Kay (New Zealand)’s email conversation about Allan Park House (per https://historicfalkland.com/the-millers-and-alans/).
I think I found out what happened to it after John Allan’s death in 1859 and then after his wife Janet Henderson’s death in 1874. The valuation roll of 1875 for Falkland, lists ‘house, garden and land’ on Lomond Hill, which I believe is referring to Allan Park House, with William Allan as proprietor and occupier (William being John and Janet’s son).
William married in 1877 (in St Ninians, Stirlingshire) with a residence on the certificate in Maryhill, Glasgow, and by 1881 is listed on the census as living in the Pleasance in Falkland.
It looks like William sold it between 1875 and 1885 as the 1885 valuation roll shows the similarly-described property as being owned by Reverend John Wilson Thomson (specifically “HOUSE GARDEN AND GROUND ALLAN PARK LOMOND HILL”.