Sony 3F-77W AM/FM portable: AA batteries don't fit(?!)

[mhardy6647]

Mrs. H has a vintage Sony 3F-77W pocket-sized AM/FM portable radio.
She decided she wanted to use it (for the first time in a long time) one day last weekend. The radio takes 3 AA sized cells (4.5 VDC).

Long story short, "modern" AA cells don't quite want to fit in the battery compartment. They are slightly too long! I can get them to work (make contact) but they are shoehorned in such a way that the 50-ish year old plastic case is stressed.

I tried two different kinds of AA cells that I found around the house (Duracell and the house-brand batteries from a regional "Big Box", Costco-like store).

Many, many years ago, I remember a similar problem with a very specific photo flash unit (Vivitar 272) and Duracell 9V batteries. Mallory (Duracell) had very slightly changed the metal shell construction on their 9V batteries, and the compartment cover on the flash wouldn't quite fit. Both companies actually delivered a solution: Mallory made a change to their batteries and Vivitar offered a replacement battery compartment cover that would accommodate slightly 'taller' batteries!

Any thoughts or ideas? Anyone else had this problem -- with AA cells and any vintage radios, that is!

Thanks!