Not Goad maps and for some reason I can't make the following link active - but I've used the old maps on this site before and although they come under Southwark, I recall some cover Forest Hill too - just might take a bit of searching on your behalf. Most are offered to download in low or high resolution - use the high option if you're going to zoom in. Some of these are very old!

http://www.southwark.gov.uk/info/200212/...outhwark/1