Framebuilders - Frame repairs - Can you help with advice?

First post on this Forum, I usually populate C&V but thought you guys might be better placed to provide practical advice on repairing this frame. It is seventy three years old - a 1935 Claud Butler sports frame built in early Reynolds 531 butted tubing. The current finish is a 1970's professional respray as far as I can tell and I am not concerned about paint damage as I wish to refinish according to the 1937 Claud Butler catalogue illustration. This one MAY be (or may not be?) the earliest surviving Claud Butler in the world! It's certainly an interesting historic machine in my opinion. I'd like to keep it going for a little longer if economically possible.

There is naturally some "battle scarring" after so many years service - the two dents shown in the left hand side of the top tube and more seriously, a crack on the inside of the right hand seat stay, just below the brake bridge.

I have no experience of frame repairs but my ideas are to fill the dents with automotive filler before repaint. In respect of the crack, rather than try to find a matching stay and have it replaced I wonder if it would be possible to drill a tiny hole at each end to stop it spreading, then have a line of brazing run along the crack between the holes? Then rub it down smooth. Or have a curved patch brazed or welded over the top?

Does anybody have any better ideas? I'd like to keep the repair as cheap as possible so I can afford the rest of the restoration. The stay does not deflect at all and the split does not open when strong hand pressure is applied to the drive side drop out in any direction. I'm assuming there's no modern "epoxy magic" type of solution and that hot work of some description will be the only remedy, but would be glad to be corrected!

Would it be better/possible to fill the dents with brazing and then file/sand down the brass fill to match the tube profile?

I don't have any experience of welding or brazing but do have a small butane/propane cannister type "blow torch" and if this could provide sufficient heat, could probably obtain some flux and brazing repair rods and have a go - or ask my neighbour, who builds motorcycles, if he can help. Otherwise it'll be an expensive professional frame builder - and none I've contacted locally seem particularly interested - "You could buy another newer frame cheaper" seems the attitude, which rather misses my point about saving a small piece of cycling history.

I tried to attach photos but even after using an on line resizing site it seems the file size is too large to post. The split is a hairline crack that runs horizontally fore and aft about 1 inch below the brake bridge. It starts (when viewed from the front) at the middle of the front of the stay and runs around the inside to the same point at the rear. At the point closest to the wheel the split is twice as wide as at the ends (say two hairs widths approx).

See next post for photos.

I'd be really grateful for any help and advice that anyone can offer.

Finally, I think I've managed to attach some photos to show the damage, hope these are helpful. The split is to the right of the first photo. The dark mark is the widest part of the split, it is a hairline crack at each end of the gap visible in the photo, as previously described. I don't believe it will now be possible to obtain a matching replacement tube. The top tube dents are shown next, then two photos of the seat cluster showing the unusual seat stay caps on the seat cluster.

This one MAY be (or may not be?) the earliest surviving Claud Butler in the world! It's certainly an interesting historic machine in my opinion. I'd like to keep it going for a little longer if economically possible.

There is naturally some "battle scarring" after so many years service - the two dents shown in the left hand side of the top tube and more seriously, a crack on the inside of the right hand seat stay, just below the brake bridge.

I have no experience of frame repairs but my ideas are to fill the dents with automotive filler before repaint. In respect of the crack, rather than try to find a matching stay and have it replaced I wonder if it would be possible to drill a tiny hole at each end to stop it spreading, then have a line of brazing run along the crack between the holes? Then rub it down smooth. Or have a curved patch brazed or welded over the top?
Since you're planning on repainting anyway, I'd use lead or silver to fill the dents -- automotive filler has a tendency to pop out and ruin your new paint job.

Re: the seat stay crack -- seat stays are not highly stressed so you could probably get away with drilling and filling with brass as you suggest. How on earth did that crack manage to appear in that spot? Was it abraded by the brake caliper, perhaps?