From Wiki

Carbic Limited, Otis King's Pocket Calculator, Model L

• Type: Cylindrical
• Size: 6.25-10.5 inches / 16-26 cm; Scale effective length 66 in / 168 cm
• Material: Steel, varnished paper scales
• Scales:
  • [ Scale 430 ] Scale 429
• HvH: 587

With eight-page folded instruction sheet and instructional brochure. Serial number A2088. This is certainly from the second series of 'A' serial numbers, following the 'Z' serial numbers. Manufactured around 1970

Take a look at the Model K page if you haven't already; the two models are mechanically identical, only the scales differ.

Where the slide on the Model K was a two-decade scale for multiplication, the Model L's Scale 430 is a single-decade scale at the top of the slide and a linear scale graduated from 0 to 1 for taking logarithms, allowing the user to go beyond simple multiplication and division. The strength of the Otis King calculator is its added precision rather than computational versatility. But, of course, you've already worked through the calculation on your Versalog and you're just coming back for an extra significant figure or two, right?

I don't see a significant difference between the Scale 429 on the Model L and the Scale 414 on the Model K.