Drop down desk

I am looking for some history and a value on this piece. 

Type: Drop-front secretary desk with glass-front bookcases
Material: Solid oak, likely quartersawn (tiger oak)
Period: Early 20th century, likely 1910s–1930s
Origin: Likely American or possibly English; the design elements and joinery are consistent with American-made pieces from the Arts and Crafts or early Colonial Revival periods
Dimensions: 48" wide x 15" deep x 45" high
Features:

• Two leaded-glass side cabinets with wooden mullions
• Central drop-down writing surface with original leather or faux-leather inlay
• Inside cubbies and drawer
• Four dovetailed drawers with carved wooden pulls and floral motifs
• Carved decorative panels on the drawer fronts and above the writing surface
• Original skeleton keys for locking compartments

Condition: Good

• Structurally sound with only minor cosmetic wear (light scratches, which are typical for its age)
• No signs of water damage or major repairs
• Original hardware and finish appear intact
• Keys included – a valuable detail for functionality and resale

Valuation Estimate (Retail / Fair Market):

• Retail (Antique Store): $650–$950 USD
• Private Party Sale: $400–$700 USD
• Auction Value (Unreserved): $300–$500 USD

Prices vary depending on geographic location, demand for Mission/Arts & Crafts or Colonial Revival styles, and condition of interior finish.

Historical & Design Significance:

• The use of carved floral drawer pulls and shell motifs atop the glass doors suggests influence from late Arts & Crafts and early Colonial Revival styles.
• The drop-front secretary format was popular in early 20th-century homes as both functional office space and elegant storage.
• The faint ink marking on the back may be a manufacturer’s inspection or production stamp, but it’s too faded to link to a specific maker.

Recommendations:

• Preservation: You may wish to use a beeswax or restorative furniture polish to enhance the finish without stripping it.
• Restoration: If refinishing is needed, preserve the original patina if possible, as it affects value.
• Professional Appraisal: Only needed if you are insuring the piece as part of a high-value estate, otherwise this informal appraisal should suffice.