It is indeed a question of money. The LBD web site (http://www.kosher.org.uk) does not have the Really Kosher Food Guide up for viewing, but invites the public to order it for £10, presumably plus postage, though it doesn't say.
On the other hand, the KA kosher list is up on the web (http://www.ka.org.au/newlist/list.htm), and it does list the Sharwood's sauces, as endorsed by the LBD:
Approved by The London Beth Din. See special notes.
Must be Product of England only.
P Balti Curry Paste
P Classic Chinese Marinade
M Dhansak Cooking Sauce
P Hot Curry Paste
P Jalfrezi Cooking Sauce
M Korma Cooking Sauce
P Light Soy Sauce
P Medium Curry Paste
P Mild Curry Paste
P Rich Soy Sauce
M Spicy Tikka Masala Cooking Sauce
P Tandoori Paste
P Tenghai Sauce
M Tikka Masala Cooking Sauce
P Tikka Masala Curry Paste
(M = Milchig, P = Pareve
The "special notes" refers to this caveat from the LBD:
"Products listed in the Kashrut Guide which are neither supervised nor logo-ed have been investigated by our food technologist and approved on this basis. The investigations cover ingredients, any processing aids and shared use of equipment. They are carried our primarily by correspondence with occasional factory visits where necessary........ It is therefore preferable, whenever possible, to buy food products made under Rabbinic Supervision."
Now, any suggestions on where to buy these sauces in the NYC area?