Hi,
You should be able to find the post war RCA's and Altec drivers ,However the pre war WESTREX,RCA stuff is very rare and you will have to be very lucky to find them.
There is a person in Bangalore who deals in this stuff on Ebay,he has the RCA field coils,westrex field coils and Lansing 287 field coil drivers.
He will sell only at top Ebay prices,he is also one of the top rated vintage sellers on Ebay.His network extends all over the country and will be able to source top quality stuff at top Ebay prices.
The south east asian dealers have also been scouring the country for tubes and vintage stuff from the late 80's.Most of the good stuff is gone but it is possible to get lucky.
Altec 288C drivers which were going for Rs 1000/ a few years back are now being quoted at Rs5000-6000/ for singles with blown diaphagrams.
A pair will set you back $200 and replacement dias from Great Plains Audio is another $200.So you are looking at about $500 for a good set of Altec 288c drivers.
Altec 802's are around Rs.500-1000 each.
Altec 416 woofers are more common than the 515 's.They will be arund Rs.1500-3000 each but will certyainly need reconing which will be around $200/ a pair from Great Plains .
The Rca's are slightly cheaper ,and most often the Diaphagrams are OK as they are phenolic but they will have the rear bakelite cover damaged.
Get in touch with an old cinema repair tech,he will be able to source stuff.For RCA try to contact the old Photophone guys.Altec was marketed by Westrex India.Klangfilm had an office both in Bombay and Madras but our friend from Bangalore bought the entire lot(tubes ,speakers crossovers etc) from them and made out like a bandit on Ebay these past few months.He sold a mono field coil speaker for over $10,000/.
Regards
Rajiv