1916 STRAITS SETTLEMENTS receipt Co Alhadad & Co affixed 1912-22 King George V Definitive 4c purple

This is a group of old receipts from Singapore dated back to 1910's to after Singapore independent.
Picture from left to right and pricelists is here:
1) STRAITS SETTLEMENTS receipt Co Alhadad & Co affixed 1912-22 King George V Definitive 4c purple $5
2) 1936 STRAITS SETTLEMENTS receipt Engineer & Contractors
LTD affixed 1912-22 King George V Definitive 4c orange for Bill nos. 11 $90 signed by Managing Director. $5
3 & 4) 1958 CPF Statement of Account To Be Retained By Member printed in 4 official languages. $6
5) 1968 PUB REMINDER Statement of Account (红单) send to 119 Joo Chiat Place 15 for outstanding amount $45.19 and cancelled 6 cents received chop.This receipt is printed in 4 official languages. $6
I understand the concern of COVID 19 and willing to provide free shipping (standard package) for the buyer. and If purchase above $50 (register package).
Stay safe and enjoy the hobby.
Tag Singapore Stamps Miniature Sheets stamp International stamp exhibition Coca cola American express Mc Donald's Readers digest swatch Siemens SIA MICROSOFT CNN INTERNATIONAL CREATIVE TECHNOLOGY Presentations pack
2015 World Stamp Exhibition Series 1 to 4 2012 to 2015 SINGAPORE