The feed dogs for the later T&S machines were flat with a rubbery coating - to handle slick fabrics better than toothy dogs. The rubber will disintegrate over time and rub off on your fabrics and it's the devil to get the stains out.

Terry at TNT Repair has replacement feed dogs in either the original rubbery stuff or the toothy type. He is THE source for all things slant - he will probably have anything you need to refurbish your 758 including a couple of books that he wrote himself. There are lots of pictures in them and they're easier for hobbyists to understand than most adjusters' manuals, which you will also need.
http://www.tandtrepair.com/index.html

I might take this on as a project machine just because it's fun to mess around with. But, I wouldn't pay much to have someone fix it. Maybe just have him put the bobbin case back in and time it and clean/oil it. If it sews well after that, you have a nice machine for $50.

It's going to be very expensive to get the gears replaced and who knows what else might be wrong with it. For the same amount of money, you can get a nice little Brother CS 6000t at Walmart.

If the bobbin case is already out, it could be that the gears were already crumbling and someone was trying to troubleshoot the problem.

It's normal for the bobbin to come apart - you unscrew them to remove what's left of the old thread on the bobbin before filling it with new thread. :)

The bobbin case can be put back in very easily. It needs to come out periodically to clean out the lint and to oil the channel on it. You can download a free manual for a 750 at www.safe manuals.com that will show you how to put it back in. The 750 just has a few more whistles and bells than the 758 but it basically operates the same way.

Thanks so much for your help.

thanks for the tips.

I just happened upon this site..... I got out my sister's old Touch and Sew and thought I had the manual but now cannot find it.... saw that you offered to copy the manual for someone else... wondered if you would do so for me??? thanks.

Lots of great replies! Now does anyone know how to fix a jammed bobbin tab on this singer touch n sew model 758 ? My old machine is in great shape, except that the rewind tab with a red bulls eye , can only be moved with extreme pressure, even after I oiled it. I'm so scared to break it- any ideas?

Found this site "Google ing" how to work this sewing machine! Just got one just like this one not too long ago, works great...except the fact I can't make it do the designs :( can anyone help me with this??? Attempting design with disc 6 Cresent Stitch.

Never mind.... It seems as though the black discs don't work, only the creme ones... At least I was doing it right ;)

The black discs should work if the others do, just possibly a different setting/adjustment. Do you have a manual to tell you what settings to use?

I'm not sure who you're talking to, but I have a digital copy of the 750 manual.

The 750 doesn't have a free-arm, so that you'll have to figure out yourself. But, I think the 750 has all the other features that were ever put into any of the Touch & Sew machines, so this might help you figure out how to operate your machine, no matter which model it is.

If yours is a very early Touch & Sew, you might do better to use the manual for a 600 machine. :)