From the Chart Supplement it seems 1O5 fails the [old] requirement for the attendant hours of Mon-Fri 10 AM to 4 PM.
1O5: Unattended
SIY: Attended Sun–Fri 1600–0100Z‡
While the attended duration is 8 AM to 5 PM (standard time) for SIY, the FBO may have intermittent, seasonal, or on-demand presence.
###Update:
But your concern is valid according to the Charting Group Meeting 15-01 – April 28 - 30, 2015:
Many pilots believe that the tick marks indicate the airport has fuel.
Over the past 20 years, many airports have gone to self- service fueling, eliminating the need for an “attendant’ to be on duty to provide fuel services.
Several airports have contacted us, requesting the tick marks be placed on their airport symbol because they have fuel.
Recommendations:
Revise the charting criteria to:
Services available – To qualify as an airport with “services available”, the minimum requirement that fuel is readily available (self-service or via attendant) 24 hrs/day.
Eliminate the requirement for attendant hours.
Outcome:
Rich Fecht, AJV-5223, reviewed the topic. Rich stated that the IACC Requirement Document has been signed and is ready to implement. Visual Charting is parsing through the data to get a list of airports that meet the fuel availability requirements and will soon start updating the VFR charts. Rich anticipates that the updated airport fueling information to be reflected on all charts within about two years. This change will affect public airports only.
That means that changes will be reflected soon.
The Chart Supplement does not have to mention temporary shortages according to IACC 8 section 3.1.5.5.4.5:
The following type data shall NOT be published in the SERVICES and REMARKS sections:
g. Temporary shortages of certain types of fuel, starting equipment, or other aircraft services;
I got the chart supplement for both airports from skyvector.com.