Ghana... a country with virtually no stamps of any value.

Anyhoo, for certain sets in the 1960s, apparently the stamps were issued in mini-sheets of 12. Scott references them in a footnote below the listing. For example, for the 1967 achievements in space set (Scott #305-307), the footnote reads as follows:
Quote:
Issued in Ghana in sheets of 30. Sheets of 12 with ornamented, inscribed border also exist; these were sold in Ghana in 1968.
Scott provides no value for these sheets. Additionally, Scott does not mention that the sheets were also printed as imperfs.
Do Michel or SG list or price these sheets?
Example of same stamp as perfed and imperfs:
