Firstly, can I apologise in advance. I am not familier with typewrter terminology.
I have had this machine a few months. I like it a lot: it is crisp and light. So far as I know no-one but me has used it since I got it. It was pretty well mint to me. Last week I noticed that two of the type bars were getting tangled: the += bar and the neighbouring 1/3bullet bar. The 1/3bullet is the last bar on the right; the += is next one in. When I press on the += key, that bar works fine; the bar moves towards the paper smoothly, and hits the paper ok, and drops back into place when I lift my finger tip. 
But, when I press on the 1/3bullet key there is a clear friction between the 1/3bullet slug (?..the letter itself) and the +=slug, although it does move ok, and hits the paper ok. But then when I take the pressure off the key, the lever does not return; the slug stays pressed against the paper and I have to bring it back with my finger on the slug. If you follow me. 
And, even then, the leading back edge of the 1/3bullet type bar comes down onto the += letter slug. And stays there, and again I have to move it over to the right with my finger to unsnag it. I have brushed the parts with meths. Makes no difference. No obvious foreign bodies. To my untrained eye it looks as if the 1/3bullet type bar might be marginally bent to the left, but that might be my imagination. Fits the symptoms, though. I am hesitant to try any ignorant cack-handed repairs without proper guidance. Any proper guidance out there?
Thank you very much, in anticipation, for your assistance.