I used to sew 27'' body carpet up with a old singer class 35 hand held machine. It was done face to face set up on a rig tensioned & pattern matched and then you manually turn the handle on the machine along the seam.
The one i used to use was massive, done face to face as you say with clamps to hold pattern. I will see if i can find pictures. Machine is maybe 30 meters long. Was use for all body carpet and stiched it to plan of a area. Any border work/designs was done with silver seam. However went by a different name and used a thinner width of tape. Was much stronger tho even tho a thinner tape than the silver seam. Started to use the same tape with my silver seam but the machine started to cook the joins as was not switching off quick enough.
Didn't have that much room in warehouse used to do 20' 30' take of and move along. A good thing sometimes when you checked and the pattern steped out less to undo and start again. Good times. Used to have to change the guides on borders an hand stitch the mitres
Yeah always fit on felt so seam beds in,it's a new Axminster carpet being fitted,spec say No silver seam or heat seam to be used , apparently if seams are sewn they are less likely to split if wet!! But I've taken carpet up with silver seam submerged in floods and it's absolutely solid? Just wondered how long it would roughly take to sew an 8mtr seam and what's the system ? The above is the only way we fit /seam in hotels or pubs its so much stronger than Tape . all be it silver seam is good and faster sewing is best .Seen to many pubs splinting due to getting wet and wear . A must is a thumb cover or thimble ive even seen fitters with rubber gloves on so you can pull the needle through, Like anything if its yur first time sewing its gonna take you longer but 8mtrs is not to bad two fitters say an hour should cover it once you have set it up .
Cheers Rob that's great advice, so is sewing still used a lot in the pub and club game . I thought it was a thing of the past as new methods have been brought out like dura fit & system 10. I know the architect was addement that no silver seam or heat seam to be used.