"NOS OEM" gaskets - any good?

I'm doing a top end rebuild on a 78 GS750. This is my first time rebuilding a motor. Love the process so far, but we'll see how I feel once I have to actually put it back together! Right now I'm needing to buy gaskets - particularly a head and cylinder gaskets. I've heard these are the ones to make sure to go OEM vs. after market. An OEM head gasket is close to 150, but I've found NOS OEM ones on eBay for closer to 60 (much easier pill to swallow). Curious to know if anyone has experience w/ these. They look identical to OEM as far as I can see. Any input is appreciated.

NOS OEM simply translate to "New Old Stock Original Equipment Manufacturer". This means that the gaskets are original equipment, likely from the 80's, that is left over from dealer stock. They will be identical to what came on the bike from the factory, just a little old and dusty. If the packaging and gaskets look undamaged they should be fine. But if the paper gaskets look dry and brittle probably no good anymore.

36 year old gaskets probably will work, but they will have hardened over the years, and may not seal as well as fresh ones.

If there are rubber seals, I doubt they would last as long ans fresh one, if they don't fall apart first.

I don't like taking engines apart just to change a gasket that is "new" and doesn't seal....

This place http://www.gasketking.com/product-category/suzuki/ doesn't list your model, but drop them a note, they may be able to make a NEW set at reasonable cost. I used their set for my CB360 and was very pleased with the quality.

50/50 shot, if they were put up well and are not brittle you can use them. I prefer new Athena gaskets, if they have what I need, i don't even look elsewhere.