Direct answer: for the classics we cover, the OEM-vs-reproduction debate is mostly settled by availability — original service panels for a 1970s FJ40, early Bronco or S30 haven't been manufactured for decades, and surviving NOS stock is scarce, expensive and often shelf-damaged. The real question is what separates a quality reproduction from a poor one.
The NOS myth
New Old Stock sounds like the gold standard, but fifty-year-old panels bring fifty-year-old problems: storage dents, surface rust under the shipping primer, and — the part nobody mentions — original factory tolerances that were never as tight as memory claims. NOS is worth chasing for date-stamped concours details; for structural steel it's sentiment at a premium price.
What 'genuine' still gets you
For late platforms like the Defender, some genuine panels remain available through heritage programs — at prices that reflect the program's overheads. They fit as well as the originals did, which experienced Land Rover builders will tell you was always approximately.
What a quality reproduction gets you
Tooling developed from measured factory panels, current-production steel with no shelf history, material matched to the original spec, availability in both LH and RH today rather than whichever side survived, and a price that makes restoring the vehicle economically sane. The fit conversation is identical for every category: trial-fit, adjust flanges as normal panel work, then paint — NOS, genuine and reproduction alike.
Where reproductions win outright
Complete structures. No factory ever sold an FJ40 tub or a jig-welded Bronco cab as a service part — reproduction assemblies exist because restorers needed something the original parts system never offered.
The judgement call
Building for concours judging on a numbers car? Hunt period-correct details where they're visible and use quality reproduction steel where they're not — judges see profiles and gaps, not steel certificates. Building a driver, a working truck or anything in between? Quality reproduction is simply the rational choice, and the money saved buys the paintwork that people actually see.