You got of for a bargain price for sure, though vintage machines go for anything from give away and up. I payed much more to get mine rewired, and that was before I found wiring scematics and tutorials on the web.
Except for the lamp, and speed controller, your 99K looks exactly like mine from 1934. When oiled and sorted out it's a nice running machine. Mine only get's noisy if I push it beyond it's limits (I tried to stitch through stiff leather, it did it, but was working noticebly harder). It's quite a tough machine, has no problems with hemming jeans, sheer silks to heavier fabrics with flawless result.
When you clean and oil you have to slide the bobbin cover completely off. Under there is a lever you lift slighly up and towards you; it releases the bobbin case. There's lots of oil points from top to bottom, under the face plate etc.
Last edited by Mickey2; 12-31-2019 at 05:20 AM.