Dress Dilemma

My bff from high school is getting married this June--SO exciting--and she's asked me to come and be a bridesmaid for her special day. I AM STOKED. I've never been a bridesmaid before--basically because I'm the only one married in my family and this is my first friend to get married. Imagine that. 

So, it is going to be a beautiful, traditional Catholic wedding and Tara's picked out a simply classic dress for her maids to wear. 

Only issue: it doesn't exactly cover my shoulders or back. 

It's a Bill Levkoff and really speaks for itself and I'm super paranoid about taking away from the dress with any alterations. 

All my (single?) ladies: we need to brainstorm. 

I'm not interested in jackets, cover-ups, or boleros--unless you can give me a killer idea for one. 

There is the one strap/trail of material that is attached in the back which is functional to use to cover me up. What do you think?

Here are a couple of ideas: 

-Use the portion of the sash that hangs off the back to attach material under the strap to hopefully make it look like the dress was meant to look like that--basically attaching a chiffon top underneath the strap, as if I was wearing an under t-shirt. 

-Cut off the strap entirely and attach some kind of sleeves. 

That's all I've got. 

Have any ideas? Would totally appreciate some input--even if it's just a pic. Actually pics are great. 

Thanks.

Here's the dress--it's in the olive-ish color, but it's actually more of a gold in person: