In terms of construction, the 526 is a near identical sister to the 527. All of the high end structural features are there like the neck joint and deep top carve, although the wood figure is typically not as vivid. This may have to do with the darker cherry wine finish.
The only real differences between the 526 and 527 are cosmetic. The 526 features a very attractive “Fern” style headstock inlay, nickel plated hardware, and the cherry wine finish color. The 526 came from the factory without a pickguard.