Industar 61 question Fed 3

The Industar 61 lense on my Fed 3 is pretty crusty and in general poor shape. Here is my possibly dumb and amateurish question.
Do all of the Industar 61 lenses have the same type of threading?
My lense is a 2.8 53. Can I buy a 2.8 55 for example and make it work/fit on my Fed 3?
Thanks, Vol

You should be fine with any Soviet/Russian/Ukrainian LTM39 lens, with the exception of some of the very very old ones (from the pre-WWII FED 1 era). Most German and Japanese LTM39 lenses should also work. Several ~50mm lenses were made for FEDs, Zorkis, and similar cameras, and you can pick them up dirt cheap on eBay -- just watch the shipping fees, since these can be a significant portion of the total cost, and a few sellers have high shipping fees. One thing to watch for, though: The Soviets also produced M39 lenses for early Zenit SLRs. These have the same thread diameter, and so can be mounted to an LTM39 rangefinder, but the ZM39 lenses have the wrong film/flange distance for a rangefinder and so won't focus properly. (They also lack rangefinder coupling.) Most eBay sellers put "FED Zorki Leica" or something similar in their titles and/or descriptions of LTM39 lenses.

Vollie,
FWIW, you might just save yourself a lot of hassle and get yourself a brand-new I-61 attached to the worlds ugliest lens cap: A FED 5
Seriously though, the more reputable dealers on eBay will sell you a new in the box FED 5 for only a little more than the lens itself; then you will have a backup body.

Just my $0.02

Kent