Seat Belt Shoulder Restraint

Just an update: I purchased a set of shoulder harness seat bets from Alpha, who were very accommodating and provided excellent service.
I look forward to installing them in my Alon soon.
Cheers,

They are easy to adjust. I have not found it too time consuming. Your passenger may need assistance. Thats about it. Highly recommended over lap belt only.

Has anyone added a shoulder restraint seat belt to their Alon/Ercoupe? I see there is a complete belt kit available for my Alon, but apparently does not include shoulder belt inertial  retractors for the shoulder strap, so would have to be adjusted manually.
Is the shoulder strap comfortable and easy to adjust, or is it restrictive without the. Inertial reels?