Gray Blazer

Front button style: button two

Button stance: classic (buttons at natural waist)

Jacket length: slightly short

Sleeve length: classic

Front darts: yes (slight waist suppression)
Color: medium gray

Lapel width: slightly wider than classic
Lapel edge: swelled
Lapel style: notch
Notch height: slightly high (but not high by today's standards)

Jetted or patch pockets: patch
Flapped or flapless: flapped
Flap height: classic

Cuff button style: button one

Vent style: single
Vent height: deep (11"; classic height is 8-10")

Shoulder: moderately padded and extended 

A Southern California chain that went out of business in 1991, so the blazer can't be any newer than that.

Age verdict: late-1960's (or very early 1970's), for 3 primary reasons:

1) the late 60's were a transitional period between the thin lapels of the early-mid-60's and the wide lapels of the 70's;
2) Deep vents started becoming popular in the late 60's;
3) Although the button one front reached its apex of popularity in the mid-60's, the button one cuff remained stylish for a couple years thereafter, even on button two and three fronts. 

Mary Tyler Moore and Dick Van Dyke

In honor of Mary Tyler Moore, who died this week at age 80, yesterday's post on one my favorite blogs, Ivy Style, showcased various 1960's styles worn on The Dick Van Dyke Show, including the button one suit. 

60's Black/Off-white Check Sport Coat

Front button style: button one

Button stance: classic (buttons at natural waist; I prefer a lower button stance, but this jacket was meant to be worn with pants at the natural waist, so it makes sense)
Button color: off-white (so it almost blends into the jacket rather than contrasting with it, as black would)

Jacket length: short

Sleeve length: short

Front darts: none (almost no waist suppression)

Lapel width: thin
Lapel style: notch
Notch shape: half-clover (straight on top, curved on bottom)
Notch height: classic
Chest pocket: none (perhaps the jacket's most minimalist touch, more so than the one button)

Color: black and off-white
Pattern: check (Does anyone have a more precise name for this check pattern? I've had two suggestions: "gingham" and simply "check".) 

Jetted or patch pockets: jetted
Straight or hacking (angled): hacking
Flapped or flapless: flapped
Flap height: short

Sleeve button style: button one
Button size: large (same size as the front button)

Vent style: double vents
Vent height: short (5")

Shoulder: somewhat padded and slightly extended (the only negative and element that's inconsistent with both the jacket's overall minimalism and the 60's American style)

Country of manufacture: USA

Anyone ever heard of this shop?

Age verdict based on all the above evidence: mid-1960's