Finally someone has found a wider bolt-on steel wheel that looks (sort of) period correct for the MGA. Think
15 x 5-1/2" with
42-mm offset.

On 3/2/2015, Sam Williams wrote:
"I don't like the look of wire wheels on our little cars. With that being said and with the issues that accompany stock MGA steel wheels, we seem to be left with but few alternatives. Mini-lites turn me off and what you have on your MG is too damn expensive for my tastes! While looking around I came across the following steel wheel: STL62509U45N (If you look it up on the Auto Zone web site you can see the specs.) .... It can also be bought at 1/2 the price Autozone sells it, but takes a bit of looking around".

For as long as the link lasts try this:
https://www.autozone.com/suspension-steering-tire-and-wheel/wheel/p/keystone-collision-wheel-stl62509u45n/187959_0_0