Jamin Darlot Lens Restorer in UK or Europe or anywhere really!

[Snapper1]

I have acquired a Jamin Darlot Cone Centralisateur Portrait Petzval 500mm F4.5 lens in need of restoration. I live in the UK so ideally, I would like to have it restored here, however, I am prepared to send it worldwide if necessary. There is balsam separation to the front element. The rack & pinion appears complete but is not working. If anyone can help or point me in the right direction I'd be grateful.
Thanks in advance

[Steven Tribe]

Sometimes rack and pinion portrait lenses have been “fixed” by the boss in the portrait studios so that the staff use the rear adjustment available on the studio camera for fine focus adjustment. Removing the 4 mounting screws will help you diagnose where the problem is.

Doing a rebalsaming of the front achromat is really a job for the owner/user - especially these days when real camera shops and servicing are no longer available. There are quite good instructions available in the DIY thread. You will need:

Approximately 100ml of zylol.

Between 1 - 3 weeks of separation time.

Domestic oven capable of 60 degree Celcius.

Small quantity of liquid Canada Balsam (same Balsam used in connection with microscope slides).

About 12 rubber bands to keep the allignment when hardening the new balsam.

Actually, work with these large achromat ( larger than 10cm) is much Easier than with smaller ones.

[Nodda Duma]

I can re-cement the doublet for you, assuming I can get the glass out of the cell. Petzvals are a breeze. I’m in the US, tho.

[Snapper1]

Thank you Steven, your advice is very much appreciated.

[Snapper1]

Thanks Nodda, I think I'll give it a go myself this time. Got to learn sometime right? I'll keep your details though, just in case! Thanks for replying.

[Steven Tribe]

Sometimes the balsam has leaked into the tiny air clearance in the brass cell so the glass is stuck. Placing the complete cell into a sealable container with xylol will loosen the lens.

Look for signs of the lenses’ history on the ground glass edge of the lens! The original ink/pencil maker’s marks are probably still there - although somewhat faded due to previous rebalsaming in the last centuries.

[Snapper1]

I'm learning quickly thanks to all your invaluable advice. Thank you.

[metcaldharv]

Thak you very much for your advice.