I re-foamed and re-capped my speakers which had 8 inch woofers several years ago. If you are reasonably handy at DIY stuff, and take reasonable care in preparation, you should be able to do the repair yourself. I am in Birmingham UK so had limited access to replacement foam surrounds like yourself. The grain on your speakers resembles mine which are also in teak veneer. Here's an extract from my thread asking for help.
I thoroughly cleaned the speaker basket of foam and glue with a box cutter work-knife and sandpaper.
I removed most of the foam and glue from the paper cone by carefully pulling it away with fingers.
I removed the stubborn remnants of glue from the cone's edge by gently digging away and pulling at it with my thumb nail, while supporting the underside of the cone with my index finger.
I decided to glue the new surround to the cone edge first. I brushed the glue onto both the cone edge and the back of the foam surround where they would make contact. While the glue was curing/setting, I tried to get the surround nice and concentric, and kept pressing the new surround to the cone edge to ensure a good seal as the glue set.
I then got the computer and amplifier set up so all would be ready to deliver a 30Hz test tone to the speaker.
I then brushed a layer of glue to the speaker basket and the back of the foam surround where they would make contact. I pressed the foam surround into place while trying to keep it nice and concentric.
Within ten minutes of doing this I connected the speaker up to the amplifier. I set the computer software to play the 30Hz test tone repeatedly.
I started with the volume fairly low but turned it up until I could see the cone vibrating and could hear the bass tone.
(On the first woofer I tackled) I heard a sort of low frequency buzzing / flapping sound. I was able to gently manoevre the foam surround until the flapping sound stopped. There was no need to completely remove the new surround and the manipulation was very minimal.
I stopped the test tone and gently pressed on the surround edge and speaker basket to get a good seal as the glue dried.
I played the test tone again to ensure that I was still getting a clean tone with no flapping.
I stopped the test tone and gently pressed on the surround edge and speaker basket to get a good seal until the glue dried.
With the second woofer there was a clean test tone at the outset.
I suggest you watch some YouTube videos of similar repairs. Try and find repairs of similar paper coned units because although the process is the same I imagine polypropylene cones are different to scrape glue from.
Here is a link to the full thread, where you may pick up other tips and avoid pitfalls, but I am sure there are many other threads to guide you through this repair. Good luck with your repair.
Refoaming AR16 speakers - help needed - Acoustic Research - The Classic Speaker Pages Discussion Forums
There is a shop in the Netherlands which can provide surrounds and glue for your AR-7
Foam surround to repair Acoustic Research AR7 woofer (speakerrepairshop.nl)