I would contact Daisy directly at the link below and ask them.
My understanding is the model 938 was a toy rifle not a bb rifle, but I did find out it was made in 1988
http://www.faqs.org/qa/qa-17374.html
Your best bet is to do a web search for 'air gun repair" and locate someone near you to repair it for you.
Which model??
We have parts for that model. gunshop@nctv.com
That model is obsolete, but we have a good selection of parts. sales@countrygunsmith.net
Try e-gunparts.com
Egunparts
I've gone through several air gun catalogues and have been unable to locate a Daisy model 170 bb gun that has ever been made. I did find a Daisy BB gun model 5170 and a BB rifle model 1170 along with a BB rifle model 107 but "NO" model 170. So here is what I suggest. Contact Daisy, They offer a service to evaluate older Daisy antiques for free. See the link below.
I suggest you contact http://www.daisy.com/contactusand ask for an owners manual. The model 799.10276 was made for Sears by Daisy and reality it is a Daisy model 25
Go to Numrich Gun Parts Corp.