classic insurance help needed

Did a quick quote through jc Taylor's website and it gave me an estimate of $176.00 a year through the antique insurance or $346.00 a year through the modified insurance. Both with $20,000.00 agreed value.

Not sure what the difference between the antique and modified are and which applies to my car. Or as to what steps I'd have to take to move forward with actually getting insurance through them if I decided to do so and as to how accurate the quote would be compared to what it would actually cost.

The quote system they use was kind of basic, didn't ask for age or other vehicles owned etc...etc.... Just basic personal and vehicle info.