If the car sat for years and years, you could have stuck piston rings. Not only would that contribute to oil burning, but it would increase blowby pressure in the crankcase and force more oil out of the PCV line. Your car does have a PCV system, which is about the only way oil is going to wind up in the intake plenum. If it's really dry and crusty, you probably have leaking valve guide seals as well.

Some of the leaking may subside with use once oil touches all the important surfaces and makes them wet again.

It also probably goes without saying, but are you sure the engine wasn't seized? If it was and you forced it, you may have scored cylinders or loose rings which would be an obvious source of crankcase pressure and oil consumption.

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]