GB 29.03.2018 Mail by Sea post & go stamps overprinted Voices from the Deep The Postal Museum, 

choice

FDC postmarked The Postal Museum London WC1, unaddressed
1, Packet Antelope FDC
2. SS Great Western FDC
3. RMS Olympic FDC

Single 1st mint
4. Single 1st stamp RMS Queen Mary
5. Single 1st stamp RMS Olympic
6. Single 1st stamp SS Britannia
7. Single 1st stamp RMS St Helena

Items 4-7 come with a photocopy receipt

If you make multiple purchases please wait for an invoice to ensure you are not overcharged on postage.