  It is known that Struve function $\mathbf H_\nu$ and modified Struve function
$\mathbf L_\nu$ are closely connected to Bessel function of the first kind
$J_\nu$ and to modified Bessel function of the first kind $I_\nu$ and possess
representations through higher transcendental functions like generalized
hypergeometric ${}_1F_2$ and Meijer $G$ function. Also, the NIST project and
Wolfram formula collection contain a set of Kapteyn type series expansions for
$\mathbf L_\nu(x)$. In this paper firstly, we obtain various another type
integral representation formulae for $\mathbf L_\nu(x)$ using the technique
developed by D. Jankov and the authors. Secondly, we present some summation
results for different kind of Neumann, Kapteyn and Schl\"omilch series built by
$I_\nu(x)$ and $\mathbf L_\nu(x)$ which are connected by a Sonin--Gubler
formula, and by the associated modified Struve differential equation. Finally,
solving a Fredholm type convolutional integral equation of the first kind,
Bromwich--Wagner line integral expressions are derived for the Bessel function
of the first kind $J_\nu$ and for an associated generalized Schl\"omilch
series.
