In general, I agree....Except for a spare, known good, MAF, Coil and Ignition and computer. I have successfully used those spare parts to trouble shoot my car and a half dozen other TR's on many occasions. These aging cars are not as reliable as they were and, frequently, drivability problems point only vaguely to the problem part(s)
Those spare, known good parts, used for troubleshooting have saved my friends and me a lot of wasted effort and expense chasing/solving drivability problems. It reduces down time too.
No flames intended here.
I'm assuming you meant 'Ignition' the second time you mentioned 'coil'....Yes, I'd keep a known good one for those unscheduled emergencies.
P.S. The dielectric grease Gary suggests will pay dividends next time you take the plug wires off. Big dividends!