If that is mm spacing then a farthing. Makes sense given the weights. Old sterling pennies were 1.4g down to 1g ish, so 1/4g =1/4 penny. Do you have any reference books? Just wondering because by Eliz.1 the penny was about 0.5g, but that had declined over a long period. Coin values are determined by the diameter of the inner circle because the outer one is too susceptible to spreading when struck.
Rules for the future:
1. Get a Withers small change book.
2. Get a Withers small change book.
3. Get a Withers small change book.
4. Get a Withers small change book.
5. Get a Withers small change book.
The surplus suggestions are to cover the 4 periods contained within the volume set, and allow me to book some copy and paste replies without having to make any other contributions. They cover Ed1 - Ed.2; Ed.3-R1; Henry 4-6;Ed.4 - Henry 7 and Henry 8-Commonwealth. You don't have to buy every one at the same time unless they are offering a discount to clear some stock. It is the best reference available and is regularly updated. Worse advise (sic) is available on ebay from some aspiring millionaire who found this in granny's change the other day, conveniently overlooking the moneyer Grunal. Hint. This is Dave Greenhalgh's name for coins he has made, (legitimately for the purpose of demonstrating hammered minting techniques).