This is the Marbles tang sight on the 30" 1899B I posted yesterday. I believe it is a S1 or S1 equivalent.

What is the correct way to raise it up? (I don't want to do something dump and break it).

Keith, hold the sight down and pull out on the little piece with the hook end, the sight then should move to the upright position under spring power. In the upright position you should be able to push the sight forward or back and it sh0ould spring back to the upright position. The 'should' 's are used because these are often found with the spring unwound and out of position. Yours looks to be siting really low so there might be a problem with the spring, because of the spring there usually is a little more clearance showing in the folded position.

Thanks Gene, worked like a charm no issue. I also was able to loosen the lower lock knurl and raise and lower the aperture ... all is good!

KeithNyst. nice gun. I have the same one. I'm looking for a replacement rear sight as mine has been soldered together previously and it would be good to be able to adjust the sight instead of having to compensate before each shot.

The gun is from my great grandfather and I'm lucky to have the 410 barrel and the case etc



Can anybody help with source for s1 sight and any other suggestions
regards

you should be able to melt the solder out to get it working

Thanks for suggestion- regards fred