Proof "Less than ¼d.": 6d. with solid numeral "No. 1, S.F. Black" with 1d. "No. 28, S.F. Black", both affixed to large piece with printed (in black) legend and date at top as in "Less than ¼d." in the Fourth Series

Details
Proof "Less than ¼d.": 6d. with solid numeral "No. 1, S.F. Black" with 1d. "No. 28, S.F. Black", both affixed to large piece with printed (in black) legend and date at top as in "Less than ¼d." in the Fourth Series