Well what i do with metal razors is put a squirt of fairy liquid in a bowl, along with pour in hot (not boiling) water & let em sit for a couple hours, then i pour some warm water in my ultrasonic cleaner (James Products Ultra 7000) along with a couple drops more of fairy liquid, and do three cycles in the cleaner (you need to be carful with any adjustable razors with numbers or handles like the Black Super Adjustables & Black Super Speeds or Lady Gillettes as the Ultrasonic can take the coloured anodized finish off !!.... not a big deal with the numbers as you can paint them back on but the handles are a different story !)
Then use a soft tooth brush with more fairy Liquid and scrub gently in all the gaps, nooks and crannys, again be careful with Black Super Adjustables & Black Super Speeds or Lady Gillettes as harsh brushing will remove the finish.
Rinse and then let them dry (thoroughly), then genlty apply Some Peak Metal Polish then buff with a microfibre cloth, for any hard to reach areas or fine detail areas like handles, use a soft tooth brush to buff the polish off, if you have some real bad marks consider using some Autosol, but be gentle and very careful as too much rubbing and pressure and the plating can be damaged.
Then buff with a microfibre cloth, and my last touch is to use some liquid Duzz-It Polish, this seems to give a brilliant shine, then buff with a microfibre cloth and finally wash again with Fary liquid and water to remove any left over polish and dry thoroughly
JOB DONE
The main thing is just be careful and don't be too aggresive...think of how old these razors are, it can be easy to cause damage...they just need TLC, the trick is to know when enough is enough and don't try to clean to make a new razor.