Without seeing it it would be difficult to say, but the "imbedded bark" comment indicates it probably is an acrylic since acrylic has much better adhesive properties than oil.
1 1/4" white space is plenty for stretching and, if the painting substrate is in reasonably good shape there should be no damage in stretching it. When paintings are ordered through various supply houses they normally are shipped rolled and unstretched.
I'll also harp on another pet peeve of mine since I have the opportunity...
Whenever we, as framers, frame any painting...oil, acrylic, pastel, watercolour, oil pastel,...whatever the medium, it IS our responsibility to our customer and to the artist to make sure the customer is aware of the framing options available to properly preserve the artwork. Many, even on this forum, take the attitude that we only frame the work and are not responsible to educate the customer about proper varnishing techniques, etc.
I say if this is your attitude, then you are not a professional framer...maybe a carpenter capable of slapping four pieces of wood around a rectangle, but not a professional picture framer.
We are the first line of defense against improper preservation techniques and the one consumers trust with original artwork. If we don't continually educate ourselves and pass this information on to our customers, we are doing such a dis-service to our clients that, I believe, a court of law would hold us accountable.
Sorry to use such strong language to push my point, but I find it so obvious and am aghast at remarks made on this forum about the "not my responsibility" approach.
We, as a group, need to be more knowledgeable about how the work we frame is created. What materials are used and why. Our customers expect us to know this information and our claim to professionalism demands it.
I tip my hat to Anna for asking questions like this and caring about the artwork that her clients have entrusted to her.
Not knowing is not a sin...not caring is...
Alright, I'll get off my soapbox...
Dave Makielski