Can't tell precisely from the pix, but it looks like the air pump and air rail are gone, so it is not emission compliant. To reinstall those you not only have the cost of the parts, but to get the air rail back on you have to partially lift the engine out of the bay.
I owned an 84. Loved it. Sold it with about that mileage, and it has since re-appeared on this very forum some 15 or so years after I sold it.
I can tell you they need regular preventive attention. It was very reliable for me, but I spent part of one weekend a month going over most moving parts on the car. Religiously changed the oil with synthetic.
You would not want to buy this car without a thorough PDI by an experienced, knowledgeable Lotus guy. The guy who worked on my car when it needed something major has rebuilt several of these motors, and he said it is not at all uncommon for them to be needing a rebuild at about 60K to 65K, depending on how they were driven and maintained. You will hear guys getting well over 100K with no troubles, but you will also hear the opposite.
See if you can talk the guy into changing the oil, then visually inspect the oil that comes out, looking for metal shavings. Send the oil off for analysis. Get a compression check done. This is a d'ellorto carb car, so someone who know them should check them out.
These are notorious for 2nd gear syncro going out, so look for that in a test drive.
Check all the bushings, check for worn wheel bearings, check the brakes/brake lines. Take a good look at all the cooling system components. These have been known to have some radiator issues, and this car ain't no Spring chicken.
I love the G bodied cars, but anymore an absolutely stunning looking example can be hiding a hideous money pit, so I would never consider one unless there was some reasonable service history/records, and that expert PDI. Absent that, I'll just admire someone else's G bodies Esprit at car shows.
Have owned, enjoyed, appreciated, and now all gone:
1969 Europa S2 Blue
1970 Europa S2 White (my first)
1974 Europa Twin Cam Special Light Blue
1974 Europa Twin Cam Special #4380R Indigo Blue (my absolute favorite).
1984 Turbo Esprit Calypso Red
2005 Elise Starlight Black
2005 Elise Saffron Yellow
2005 Elise Ardent Red (used as development mule for the LETSLA)
2006 Exige Graphite Grey
2007 Exige S Canyon Red (first customer installation for the production LETSLA)