Although you are using a very short course which cannot be rated, now that you have given us the slopes of full length tees, can you provide the rest?
Length and SSS/CR for each.
I don't think there's a way this can be handicapped fairly.
Essentially your creating a new game which challenges your chipping/putting and ability with a 150 yard club.
One way to do it would be to look at each individuals 'stats' on the holes circa 150 yards at your course, and extrapolate a handicap from that.
