Just checked my EZ Rider in the basement.
It is the orange Arco model with out the seat shocks, also have it's brother in purple with the shocks.
Yes, the Holland tires are OEM. Very soft rubber compared to Carlisle and Goodyear, etc.
My orange
bike has the same clutch as yours with white Tec 3.5 engine.
Purple bike has black 4 hp with different and definitely newer clutch.
Grips on the Orange are the old block pattern like Heald and others had.
If I had to guess your grips are not as born.
Also my orange
bike has Leopard seat and have seen 2 others with the same, Arco used whatever they had at the time the bike was built, convinced of that.
Most of the other companies did the same as they were constantly picking up parts from other brands going out of business.
HTH
Later,
Keith