That is NOT an IBM 
   It is based on an Imperial Electric typewriter from before the days of the Litton Industries takeover (when Royal electrics were re-branded as Imperials).  The clues are in the details like the platen knobs (Imperial 70 manual) and the ribbon spools and mechanism (rather like the Imperial 80), but the biggest clue is in the photo of the electric motor which is labelled 'Imperial Electric' !  I can see why the seller thinks it is an IBM 'B' since the overall shape is similar, so maybe an easy mistake to make for a non-typewriter person.  Even without the modifications, it must be an incredibly rare machine.  I was offered one to take home when I was an apprentice in the mid-1970's and had to refuse it because my mother would have gone spare if I had dragged something this size home !

Olympia SGE-40 (Electric) on eBay in the UK.  Not wired for USA power. 


Not too often you see these for sale.

https://www.ebay.co.uk/itm/325374711053?hash=item4bc1d8150d:g:XrUAAOSwLIRjQbx2&amdata=enc%3AAQAHAAAAoIdb77s2JiMqdDYJLmo5iMFp0elykpyHdrsmYVZT0JOKEkK7XYM1u%2B2bng60QprCEd6aCf%2Fmjm0D8Wifoblpkx0t4y%2F4%2BOHsVjm7%2BFrQckXuG0ERhj0WNdJeX%2Ftdv2Z27y7blz3cixft2vJnZk6HjQxnAKgPpfxY7qfquAxJIZclM3qF6BDCC5Y14MikZ73o5eET%2FbFUWN%2Blq%2Btm%2FncDeGo%3D%7Ctkp%3ABk9SR_7WoNSEYQ

If anyone is looking for a very promising Olympia SG3 and itsnorth of MIssoula Montana....this one is only $ 50 USD and even has its plastic paper support. 

Seller states it all works and comes with an Olympia vinyl dust-cover and a typing mat for your table.

It is on FaceBook Marketplace :

https://www.facebook.com/marketplace/item/494761775713420/?hoisted=false&ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A2206210a-33bf-4925-930e-f91aeb63fbeb