Found 2 Lynch Rd Runners on Ebay.
Link to first one:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4511261434&category=43921

Title shows last 6 of 256589 and registration shows 216589. No fender tag shown. Supposedly owned by Jesse James, maybe someone can call on the build date?

Link to second one:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4511439829&category=43921

RM21H9A254049
01162 254955 9A254049

925 595 603 N96(Air Grabber Hood)

B5 B5(Blue Fire Metalic) H2X( Black interior) X9(Black velvet accent colours)

RM21(2 dr Coupe) E63(383/4bbl/335hp) D21(Heavy Duty 4 speed)

404(April/ 04/ 69) B 28914(Production Sequence)

Hope that helps some of the build date mysteries.