Colour Query On Straits Settlements Sg71

I've pulled this stamp from a recent auction lot of Whole World stamps and wonder if anyone can help.



Looking in the Gibbons Concise catalog, the only match I can find is SG71, from 1867. In fact, it's the only 96 cent stamp listed for Straits Settlements.

My problem is that it's listed as a 'grey' colour, and in reality it appears to me to have a reddish tinge (though I am slightly colour-blind which doesn't help!) It has been overstamped, 'B & CO' which I assume is a company security overstamp, similar in use to perfins.

So, a couple of questions:

1. Is this really an SG71 Grey, or do I have a weird colour anomaly?
2. Catalog value, used is shown as £50. Obviously this is only a catalog value, but would that be adjusted, positively or negatively by the security overprint? Not selling, just curious.
3. Any ideas what 'B & CO' could relate to?

Many thanks for helping a newbie.

3. Boustead and Co

Many thanks for that.

There's an interesting article on Wikipedia about the company. They're still going strong today!

Concise is a GB Catalogue. Did you mean Commonwealth?

SG71 in the 2007 Commonwealth and Empire is listed as 'olive-grey.' That looks about correct. I am assuming you checked the watermark ('CA' and not 'CC') to eliminate SG19.

> Concise is a GB Catalogue. Did you mean Commonwealth?

Sorry, no. Just checked and the catalogue I have here is the Simplified Stamps of the World (2007).

SG71 is just listed there as Grey. No SG19 is listed in Simplified. I've checked in Scott's (2017) too since, where both versions are listed as Olive Grey. Mine is the Crown and CA watermark.

I'll obviously have to track down a Commonwealth catalogue now. So many different catalogues!!

This is my highest (catalogue) value stamp to date, so thanks for the help and advice. Just question 2 left now: Would the 'B&Co' overprint increase or decrease the value?

Crown CA is SG71. That is listed as olive-grey in the Empire & Commonwealth.
Crown CC is SG 19 (1867 - 1872 series) and is listed as 'grey.'

Different catalogues may list different colours. Even Stanley Gibbons does not use the same colours for the same stamp across its catalogues. And I am not even looking at the same catalogue over the years.

The purple ink, normally, indicates fiscal use. However, I understand in some commonwealth countries - my area is GB & Ireland - it also was used as security overprint to prevent theft. That may fit your stamp since it appears to have a postal cancel.
If it is fiscal use, it, normally, devalues the stamp.
If it is a security overprint and postal use, I cannot say. It is not my area of experience.

Edit: info on SG19.

many thanks again NSK.

All useful info for someone who buys what are essentially 'schoolboy collections' at auction. I obviously have a great deal to learn!