What do protestants who believe our old bodies will be resurrected think that will look like?

Jas 3.1 I think your question has no definite answer as the Bible does not say. I agree with what Mawia essentially said but I'd like to point out that in the extra scriptural accounts of heaven by Jessie Duplantis Kat Kerr Rebecca Springer. They, to the best of my knowledge, believed the old bodies would be reassembled fixed and come out of the ground. They describe a "perfect" age height weight ect which people are in heaven. Children are said to age in heaven at a decelerated rate (sometimes to match the arrival of their parents in Heaven) till they reach the "perfect" age. In some accounts your appearance reflects the service and wisdom you held for the Master. Wiser wouldn't mean older exactly just more respect. But Rebecca Springer thought that ones experience of heaven while shared with others is largely personal.

While I do not believe our bodies will be impeded or broken there is nothing which specifically states that we will not be able to carry battle scars from our service on the earth.

Gal 6:17 From henceforth let no man trouble me: for I bear in my body the marks of the Lord Jesus.

Paul bore in his body the marks of Christ I don't think he would want to loose them but I'm sure he wouldn't mind if that was the way it had to be.

esv Col 1:24 Now I rejoice in my sufferings for your sake, and in my flesh I am filling up what is lacking in Christ’s afflictions for the sake of his body, that is, the church,

If we suffer persecution and afflictions not because of our self but for Christ we are participating in His sufferings. We may very well keep those scars which we receive because of His Name for the Church. Having the underlying condition which cause the scar removed. Eternal honor badges.

But like I said the scripture does not say its just a guess.

This long passage may be sufficient to answer the question.

1 Corinthians 15:35-54 (NIV)

But someone will ask, “How are the dead raised? With what kind of body will they come?” How foolish! What you sow does not come to life unless it dies. When you sow, you do not plant the body that will be, but just a seed, perhaps of wheat or of something else. But God gives it a body as he has determined, and to each kind of seed he gives its own body. Not all flesh is the same: People have one kind of flesh, animals have another, birds another and fish another. There are also heavenly bodies and there are earthly bodies; but the splendor of the heavenly bodies is one kind, and the splendor of the earthly bodies is another. The sun has one kind of splendor, the moon another and the stars another; and star differs from star in splendor.

So will it be with the resurrection of the dead. The body that is sown is perishable, it is raised imperishable; it is sown in dishonor, it is raised in glory; it is sown in weakness, it is raised in power; it is sown a natural body, it is raised a spiritual body.

If there is a natural body, there is also a spiritual body. So it is written: “The first man Adam became a living being”; the last Adam, a life-giving spirit. The spiritual did not come first, but the natural, and after that the spiritual. The first man was of the dust of the earth; the second man is of heaven. As was the earthly man, so are those who are of the earth; and as is the heavenly man, so also are those who are of heaven. And just as we have borne the image of the earthly man, so shall we bear the image of the heavenly man.

I declare to you, brothers and sisters, that flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. Listen, I tell you a mystery: We will not all sleep, but we will all be changed — in a flash, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, the dead will be raised imperishable, and we will be changed. For the perishable must clothe itself with the imperishable, and the mortal with immortality. When the perishable has been clothed with the imperishable, and the mortal with immortality, then the saying that is written will come true: “Death has been swallowed up in victory.”

Many protestant preachers say that our body will be reconstructed from the remains of our body from the grave or where ever it is. The one that was blown up in a bomb explosion will also be recollected and rebuild from ashes. But it will be transformed to a heavenly body. That is what exactly this passage is talking about. The heavenly body will not look the same like the old one. A person who was born without legs will have two perfect legs. A blind person will no longer be blind and the deaf person will hear too.

I heard from many protestant preachers that the reason why Jesus still has the scars on his body is to keep it as a remembrance that Jesus suffered and died for us. The scars were left there intentionally on purpose.