Lovely, decorative scrolls.
Those are the distinctive 'floral' scrolls on the side of the shoebox-style Comptometers. Taking a break from the Marchant Pony B, moved to tackling a Comptometer Model B.
Older Comptometers are becoming rather hard to find, but last year managed to get a Model B for a reasonable outlay. The reason it was reasonable, was that it looked rather bad. It seemed mostly complete, but some 'wrong' keys, covered in black paint and -judging from clearing handle- possibly blocked.
Now taking the acquisition out of storage, proceeded to open it up. The clearing handle was stuck solid on its shaft, only heat-cycling (soldering-iron) finally made it budge. As can happen with Comptometers, the mechanism was glued/melted firmly to the case-lining. That took time and force to break it free. After those challenges, it all came apart fairly easily.
With some columns already taken out in the above image, it's obvious that the machine was painted black without taking off the keys. The dark area of the keys is the original, heavily corroded/patina copper finish. The black paint also was 'irregular' with many specks/spots - that could be rust underneath, but proved to be simply dirt and dust embedded in the paint.
Screws had also been painted-over.
Did not want to leave the case this way; so first removed the old, black paint. Paint can be removed in several ways, e.g. lye or acetone or specialised paint-stripper formulas. With older paints, a least-aggressive method that often works is simply hot water. Much safer than other methods and no problem then to leave the cork+linoleum lining in-place.
In this case hot water worked brilliantly. Place the panel in a container, e.g. a large baking-tray. Then pour boiling water onto it and leave it in the hot bath for about 10 - 15 minutes. The black paint could then be peeled off, revealing the state of the machine at the moment it was decided to cover it in black paint. Some areas still serviceable, but all corners and the top-front panel had been rusty.
Another benefit of the boiling hot water treatment is that the cork-linoleum lining turns soft and malleable. That allowed it to be flattened again, by letting it all cool off with weights (bricks) on the lining.
Fine water-proof sandpaper was used to slightly roughen-up the surface for adhesion and also smoothen rusted areas, then all panels were re-finished in a metallic copper-brown.
Glare makes it hard to get an impression from the above image, but attempted to get the colour within the variations that occur over time with Comptometers. Toom a few panels on a trip to the auto-parts store, to select a close, matching metallic lacquer.
In the end, settled on using two spraycans. The Motip colour 51530 is very close, but has too much of a reddish hue. Spraying on a coat of the darker colour 51200 then followed by a coat of 51530 on the still-wet lacquer results in a decent, mix colour with less of the reddish overtones. The slight variations in colour over a panel that result from this 'manual-mixing' were found to be fine, similar variations are found on original panels (from variation in thickness of the original lacquer and from usage too).
The re-finished front-panel here on top of a Model J - it of course varies with different lighting, but overall the lacquer is a credible match.
The decimal-pointers on the front-panel were by the way not taken off, but masked with tape. Between applying coats of paint, the pointers were shifted to different positions. Net-result is that there is lacquer also underneath all the pointer positions (but fewer layers, of course).
After cleaning all the screws, the box was re-assembled and looks much better. All ready for the mechanism to be tackled next.
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