As Joe stated, such decisions should be based on the remaining condition of the fabric. A jib/genoa sail that has been overstressed and will typically have its foot and leech permanently stretched; plus, you should carefully examine the conditions of the tack and clew cringles for signs of excess wear and tear ... indicating high use.
When evaluating a sail thats been on a roller furler for a long time, what you should be looking for is UV 'burn' or a weakness of the fabric due to sun exposure, even if there is a 'sun cover'. How to do this is: first look for zones of broken or sun damaged polyester stitching ... stitching that needs to be replaced will look old and 'greyish' - look at the stitching near the leech as flogging is the chief destroyer of stitching.
Then take a screwdriver and attempt to push it through the fabric at the 'corners', but not in the area of the 'patches' but just beyond them in the unsupported areas - head, tack, and clew. A thoroughly sun weakened sail will allow the screwdriver, etc. to easily penetrate *through* the fabric without much force. The 'corners' of any sail are the zones of where the highest stress and any weakness in the fabric will show up in these places before any other areas.
Sails are 3 dimensional surfaces; that curvature (so-called belly) determines where the zone of maximum draft occurs. To evaluate jibs/genoas, have 3 persons each pulling on a corner pull the sail off the ground and simply see approximately where the 'maximum draft' (belly) occurs ... it should be at approximately 30-40% of the chord length back from the luff. Then, while holding and tensioning those 3 corners look at the shape of the leech ... it should be essentially flat; not cupping up nor sagging toward the ground .... FLAT. The worst shape will be when those corners are pulled and with the sail off the ground is a leech that is sagging towards the ground, not 'flat'.
From the pics but without seeing where the point at which that maximum draft is located ... it initially looks like a decent sail to me based on the pic. The real key in evaluation is remaining sail cloth quality.
For foam luffs, ... they only last a few years before the foam permanently deforms in a compressed state. Foam luffs normally are replaced every 5, etc. years. The foam luff on the sail in the pic, to me, looks to be too damn small and doesnt extend far enough aft of the luff ... but Id really need to see how the sail 'rolls up' on a furler to be sure.
I wish I was there to feel it but can only go by pics.......
